1
1996
... A biomaterial is defined as a material intended to interface with biological systems to evaluate, treat, augment or replace any tissue, organ or function of the body.1, 2 Commonly, pacemakers, stents, sutures, bone plates and screws, needles, knee joints and catheters all constitute biomaterials. Biomaterials are used across a wide range of applications and have become a major industry in the 21st century. The traditional metallic biomaterial requires that metals are as inert as possible in order to minimise the immune response and reduce the corrosion of the material itself in the physiological environment of the body. Typically, these biomaterials are stainless steels, titanium (Ti) alloys and cobalt-chrome-based alloys. After decades of developing improved corrosion-resistant metallic biomaterials, the design and application of biodegradable metals are currently under the spotlight. A biodegradable material is expected to degrade gradually in vivo, with an appropriate host response elicited by released corrosion products, and then to dissolve completely upon fulfilling the mission of assisting with tissue healing while leaving no implant residues.3 The materials should be non-toxic or made up of metallic elements which can be metabolised by the human body. Therefore, magnesium (Mg)-based biodegradable alloys are a promising material for clinical applications. ...
Biomaterials: the intersection of biology and materials sceince
1
2008
... A biomaterial is defined as a material intended to interface with biological systems to evaluate, treat, augment or replace any tissue, organ or function of the body.1, 2 Commonly, pacemakers, stents, sutures, bone plates and screws, needles, knee joints and catheters all constitute biomaterials. Biomaterials are used across a wide range of applications and have become a major industry in the 21st century. The traditional metallic biomaterial requires that metals are as inert as possible in order to minimise the immune response and reduce the corrosion of the material itself in the physiological environment of the body. Typically, these biomaterials are stainless steels, titanium (Ti) alloys and cobalt-chrome-based alloys. After decades of developing improved corrosion-resistant metallic biomaterials, the design and application of biodegradable metals are currently under the spotlight. A biodegradable material is expected to degrade gradually in vivo, with an appropriate host response elicited by released corrosion products, and then to dissolve completely upon fulfilling the mission of assisting with tissue healing while leaving no implant residues.3 The materials should be non-toxic or made up of metallic elements which can be metabolised by the human body. Therefore, magnesium (Mg)-based biodegradable alloys are a promising material for clinical applications. ...
Biodegradable metals
3
2014
... A biomaterial is defined as a material intended to interface with biological systems to evaluate, treat, augment or replace any tissue, organ or function of the body.1, 2 Commonly, pacemakers, stents, sutures, bone plates and screws, needles, knee joints and catheters all constitute biomaterials. Biomaterials are used across a wide range of applications and have become a major industry in the 21st century. The traditional metallic biomaterial requires that metals are as inert as possible in order to minimise the immune response and reduce the corrosion of the material itself in the physiological environment of the body. Typically, these biomaterials are stainless steels, titanium (Ti) alloys and cobalt-chrome-based alloys. After decades of developing improved corrosion-resistant metallic biomaterials, the design and application of biodegradable metals are currently under the spotlight. A biodegradable material is expected to degrade gradually in vivo, with an appropriate host response elicited by released corrosion products, and then to dissolve completely upon fulfilling the mission of assisting with tissue healing while leaving no implant residues.3 The materials should be non-toxic or made up of metallic elements which can be metabolised by the human body. Therefore, magnesium (Mg)-based biodegradable alloys are a promising material for clinical applications. ...
... Suitable alloying elements need to be tailored to design and improve the mechanical and bio-corrosion properties of biomedical Mg alloys. Table 4 shows a brief summary of the various alloying elements used in Mg biomaterials.3, 38, 69-85 Alloying elements can strengthen the Mg alloys by solid solution strengthening, precipitation hardening and grain refinement strengthening. These alloying elements must have high and temperature-dependent solubility in Mg. High solubility of an alloying element can lead to significant precipitation hardening of Mg alloys, such as Mg-Al alloys, Mg-Zn alloys and Mg-rare earth (RE) alloys. Both solid solution strengthening and precipitation strengthening improve the strength, but generally cause deterioration in the ductility of Mg alloys. However, grain refinement strengthening improves both strength and ductility. It is widely acknowledged that the refinement efficiency of the alloying elements can be determined by their growth restriction factor.86-88 The growth restriction factor is a measure of the segregation power of an element during solidification. It is calculated from binary phase diagrams and equals ΣimiC0,i (ki﹣1), where mi is the slope of the liquidus line (assumed to be straight), ki is the distribution coefficient and C0,i is the initial concentration of element i.89 If an element has a large growth restriction factor (such as Zr, Ca, Zn) this means that the growth-restricting effect on the solid-liquid interface of the new grains is strong, thus preventing new grains from growing into the melt.90 These elements segregate strongly in the melt and cause intense constitutional supercooling in a diffusion layer ahead of the advancing solid/liquid interface, consequently promoting nucleation and restricting grain growth. Therefore, these elements can significantly refine the grains, which benefits both strength and ductility. ...
... Note: Superscript a indicates that the total amount of rare earth elements (Ce, La, Nd, Pr, Y) should not exceed 4.2 mg/day. Data are from Zheng et al.3, 38, 69-85 ...
1
1999
... Bone is a hard biological tissue formed of cells embedded in a matrix, which consists of an organic (90% collagen and 10% amorphous) ground substance reinforced by a mineral phase. Calcium phosphate (Ca3(PO4)2) and calcium carbonate (CaCO3) are the main constituents of bone mineral. Bone serves as a protector for organs and provides mechanical stability to the body, making movement possible. There are two types of bone, cortical (compact or Haversian) and cancellous (spongy or trabecular) bone.4, 5 ...
Evaluation on bending properties of biomaterial GUM Metal meshed plates for bone graft applications
1
2017
... Bone is a hard biological tissue formed of cells embedded in a matrix, which consists of an organic (90% collagen and 10% amorphous) ground substance reinforced by a mineral phase. Calcium phosphate (Ca3(PO4)2) and calcium carbonate (CaCO3) are the main constituents of bone mineral. Bone serves as a protector for organs and provides mechanical stability to the body, making movement possible. There are two types of bone, cortical (compact or Haversian) and cancellous (spongy or trabecular) bone.4, 5 ...
Evolution of fracture treatment with bone plates
2
2018
... Bone remodelling is a continuous process of bone resorption and formation, to provide maximum strength with minimum mass. Bone has a strong capability to regain its lost strength through the healing process. However, the internal fixation of broken bones only became possible via aseptic techniques for open fracture reduction and direct fixation with metallic hardware.6 Thus, supportive orthopaedic implants are necessary to fix the bone when a fracture occurs. Orthopaedic implants are medical devices which can be used to replace or provide fixation of bone, or replace the articulating surfaces of a joint. Typically, orthopaedic implants include plates, nails and screws. Fracture fixation is used to reduce interfragmentary movement. ...
... The principle of meticulous anatomical reduction of each fracture fragment by direct fracture exposure and subsequent fixation by compression plating, as practised by surgeons through the 1980s,9 required extensive soft tissue intervention. The application of locking plates coincided with the development of minimally-invasive fracture fixation, which has resulted in important changes in fracture management.6, 10 The most common treatment options for the fixation of fractures are locking compression plates and interlocking nails, as shown in Figure 1.11, 12 ...
Plating of the distal radius
1
2005
... There are several types of plates: compression plates, buttress plates, neutralisation plates and bridging plates. Compression plates are used to bring the two fracture ends of the bones close to each other and provide sufficient stability using dynamic pressure between the fragments, which promotes bone healing. Buttress plates are especially used around joints (such as knees and ankles) to hold together fractures at the ends of long bones; preventing axial forces from distorting the initial reduction.7 These plates can be moved with the body because they are contoured. Neutralisation plates are a category of plate which bridges the fracture and protects the screws or other devices from bending and torsional loading.8 Bridging plates are designed to provide stability when multi-fragmentary long bone fractures occur; they can offer the correct length and alignment and promote secondary bone healing.8 This is because they preserve the blood supply to the fragments without disrupting the damaged area. ...
AO Foundation Surgery Reference
4
2021
... There are several types of plates: compression plates, buttress plates, neutralisation plates and bridging plates. Compression plates are used to bring the two fracture ends of the bones close to each other and provide sufficient stability using dynamic pressure between the fragments, which promotes bone healing. Buttress plates are especially used around joints (such as knees and ankles) to hold together fractures at the ends of long bones; preventing axial forces from distorting the initial reduction.7 These plates can be moved with the body because they are contoured. Neutralisation plates are a category of plate which bridges the fracture and protects the screws or other devices from bending and torsional loading.8 Bridging plates are designed to provide stability when multi-fragmentary long bone fractures occur; they can offer the correct length and alignment and promote secondary bone healing.8 This is because they preserve the blood supply to the fragments without disrupting the damaged area. ...
... 8 This is because they preserve the blood supply to the fragments without disrupting the damaged area. ...
... The principles of locking compression plates, nails and screws are illustrated in Figure 2.8 A locking plate provides fixation with absolute stability for two-part fracture patterns, where the bone fragments can be compressed.13 Furthermore, the addition of an orthopaedic screw across the fracture and through the plate enhances the stability. Orthopaedic screws are used to tighten up damaged areas, which are one of the tenets of orthopaedic fixation. They reduce the gap between the bones. Lag screws are used to achieve interfragmentary compression, which protects the fractured bone from bending, being rotated and from trivial loading forces. The interlocking nail is basically an intramedullary pin, providing absolute stability to maintain alignment and position, including the prevention of rotation.14 The mechanical properties of an implant significantly affect the stability of fracture fixation provided by orthopaedic implants/devices. ...
...
8
Common metallic alloys for orthopaedic application Ti, stainless steel and cobalt-chromium (Co-Cr) alloys have been employed as permanent implants. Stainless steel and Co-Cr alloys are the first generation of inert metallic implants. Stainless steel has been used to manufacture bone plates, screws and pins, which have excellent mechanical properties but high modulus and poor wear resistance. Co-Cr alloys have good mechanical properties and superior corrosion resistance, but high modulus and are difficult to machine. Ti alloys are ‘second generation’ and are used for fracture fixation and femoral hip stems. Ti alloys have excellent corrosion resistance, good biocompatibility and high mechanical strength, but poor wear resistance, poor bending ductility and come at a high cost.15 The objective of orthopaedic implants is to produce absolute stability, abolishing all interfragmentary motion. The implant material must have adequate mechanical properties. The mechanical performance characteristics of unalloyed Ti, stainless steel and Co-Cr alloys for surgical implant applications are listed in Table 1.16-18 ...
Why and how do locking plates fail?
1
2018
... The principle of meticulous anatomical reduction of each fracture fragment by direct fracture exposure and subsequent fixation by compression plating, as practised by surgeons through the 1980s,9 required extensive soft tissue intervention. The application of locking plates coincided with the development of minimally-invasive fracture fixation, which has resulted in important changes in fracture management.6, 10 The most common treatment options for the fixation of fractures are locking compression plates and interlocking nails, as shown in Figure 1.11, 12 ...
Evolution of the internal fixation of long bone fractures. The scientific basis of biological internal fixation: choosing a new balance between stability and biology
2
2002
... The principle of meticulous anatomical reduction of each fracture fragment by direct fracture exposure and subsequent fixation by compression plating, as practised by surgeons through the 1980s,9 required extensive soft tissue intervention. The application of locking plates coincided with the development of minimally-invasive fracture fixation, which has resulted in important changes in fracture management.6, 10 The most common treatment options for the fixation of fractures are locking compression plates and interlocking nails, as shown in Figure 1.11, 12 ...
... 2) A hydrogen evolution method has been developed by Song et al.182 based on the collection of hydrogen gas during degradation of Mg in aqueous solutions. The hydrogen evolution measurement is currently very popular and is widely accepted by many researchers.10, 42, 59, 106, 107, 178-181 The mechanism of this measurement is simple and easy to understand, and is based on the reaction below: ...
Are locking plates better than non-locking plates for treating distal tibial fractures?
2
2014
... The principle of meticulous anatomical reduction of each fracture fragment by direct fracture exposure and subsequent fixation by compression plating, as practised by surgeons through the 1980s,9 required extensive soft tissue intervention. The application of locking plates coincided with the development of minimally-invasive fracture fixation, which has resulted in important changes in fracture management.6, 10 The most common treatment options for the fixation of fractures are locking compression plates and interlocking nails, as shown in Figure 1.11, 12 ...
...
11 Copyright 2014 European Foot and Ankle Society. (C) Interlocking nail. (D) Radiograph of femoral fracture treated with locking nail. Reprinted from Hsu et al.
12 Copyright 2019, with permission from Elsevier.
The principles of locking compression plates, nails and screws are illustrated in Figure 2.8 A locking plate provides fixation with absolute stability for two-part fracture patterns, where the bone fragments can be compressed.13 Furthermore, the addition of an orthopaedic screw across the fracture and through the plate enhances the stability. Orthopaedic screws are used to tighten up damaged areas, which are one of the tenets of orthopaedic fixation. They reduce the gap between the bones. Lag screws are used to achieve interfragmentary compression, which protects the fractured bone from bending, being rotated and from trivial loading forces. The interlocking nail is basically an intramedullary pin, providing absolute stability to maintain alignment and position, including the prevention of rotation.14 The mechanical properties of an implant significantly affect the stability of fracture fixation provided by orthopaedic implants/devices. ...
Interlocking nailing of femoral shaft fractures with an extremely narrow medullary canal is associated with iatrogenic fractures
2
2019
... The principle of meticulous anatomical reduction of each fracture fragment by direct fracture exposure and subsequent fixation by compression plating, as practised by surgeons through the 1980s,9 required extensive soft tissue intervention. The application of locking plates coincided with the development of minimally-invasive fracture fixation, which has resulted in important changes in fracture management.6, 10 The most common treatment options for the fixation of fractures are locking compression plates and interlocking nails, as shown in Figure 1.11, 12 ...
...
12 Copyright 2019, with permission from Elsevier.
The principles of locking compression plates, nails and screws are illustrated in Figure 2.8 A locking plate provides fixation with absolute stability for two-part fracture patterns, where the bone fragments can be compressed.13 Furthermore, the addition of an orthopaedic screw across the fracture and through the plate enhances the stability. Orthopaedic screws are used to tighten up damaged areas, which are one of the tenets of orthopaedic fixation. They reduce the gap between the bones. Lag screws are used to achieve interfragmentary compression, which protects the fractured bone from bending, being rotated and from trivial loading forces. The interlocking nail is basically an intramedullary pin, providing absolute stability to maintain alignment and position, including the prevention of rotation.14 The mechanical properties of an implant significantly affect the stability of fracture fixation provided by orthopaedic implants/devices. ...
The concept of locking plates
1
2010
... The principles of locking compression plates, nails and screws are illustrated in Figure 2.8 A locking plate provides fixation with absolute stability for two-part fracture patterns, where the bone fragments can be compressed.13 Furthermore, the addition of an orthopaedic screw across the fracture and through the plate enhances the stability. Orthopaedic screws are used to tighten up damaged areas, which are one of the tenets of orthopaedic fixation. They reduce the gap between the bones. Lag screws are used to achieve interfragmentary compression, which protects the fractured bone from bending, being rotated and from trivial loading forces. The interlocking nail is basically an intramedullary pin, providing absolute stability to maintain alignment and position, including the prevention of rotation.14 The mechanical properties of an implant significantly affect the stability of fracture fixation provided by orthopaedic implants/devices. ...
Practical Fracture Treatment
1
2008
... The principles of locking compression plates, nails and screws are illustrated in Figure 2.8 A locking plate provides fixation with absolute stability for two-part fracture patterns, where the bone fragments can be compressed.13 Furthermore, the addition of an orthopaedic screw across the fracture and through the plate enhances the stability. Orthopaedic screws are used to tighten up damaged areas, which are one of the tenets of orthopaedic fixation. They reduce the gap between the bones. Lag screws are used to achieve interfragmentary compression, which protects the fractured bone from bending, being rotated and from trivial loading forces. The interlocking nail is basically an intramedullary pin, providing absolute stability to maintain alignment and position, including the prevention of rotation.14 The mechanical properties of an implant significantly affect the stability of fracture fixation provided by orthopaedic implants/devices. ...
Biomedical applications of titanium and its alloys
1
2008
... Ti, stainless steel and cobalt-chromium (Co-Cr) alloys have been employed as permanent implants. Stainless steel and Co-Cr alloys are the first generation of inert metallic implants. Stainless steel has been used to manufacture bone plates, screws and pins, which have excellent mechanical properties but high modulus and poor wear resistance. Co-Cr alloys have good mechanical properties and superior corrosion resistance, but high modulus and are difficult to machine. Ti alloys are ‘second generation’ and are used for fracture fixation and femoral hip stems. Ti alloys have excellent corrosion resistance, good biocompatibility and high mechanical strength, but poor wear resistance, poor bending ductility and come at a high cost.15 The objective of orthopaedic implants is to produce absolute stability, abolishing all interfragmentary motion. The implant material must have adequate mechanical properties. The mechanical performance characteristics of unalloyed Ti, stainless steel and Co-Cr alloys for surgical implant applications are listed in Table 1.16-18 ...
Standard specification for unalloyed titanium, for surgical implant applications
2
2006
... Ti, stainless steel and cobalt-chromium (Co-Cr) alloys have been employed as permanent implants. Stainless steel and Co-Cr alloys are the first generation of inert metallic implants. Stainless steel has been used to manufacture bone plates, screws and pins, which have excellent mechanical properties but high modulus and poor wear resistance. Co-Cr alloys have good mechanical properties and superior corrosion resistance, but high modulus and are difficult to machine. Ti alloys are ‘second generation’ and are used for fracture fixation and femoral hip stems. Ti alloys have excellent corrosion resistance, good biocompatibility and high mechanical strength, but poor wear resistance, poor bending ductility and come at a high cost.15 The objective of orthopaedic implants is to produce absolute stability, abolishing all interfragmentary motion. The implant material must have adequate mechanical properties. The mechanical performance characteristics of unalloyed Ti, stainless steel and Co-Cr alloys for surgical implant applications are listed in Table 1.16-18 ...
... Note: Superscript a indicates a different grade of CP Ti which often means a different oxygen content. Data are from ASTM International.16-18 ...
Standard specification for wrought 18chromium-14nickel-2.5molybdenum stainless steel bar and wire for surgical implants
2020
Standard specification for wrought cobalt-28chromium-6molybdenum alloys for surgical implants
2
2020
... Ti, stainless steel and cobalt-chromium (Co-Cr) alloys have been employed as permanent implants. Stainless steel and Co-Cr alloys are the first generation of inert metallic implants. Stainless steel has been used to manufacture bone plates, screws and pins, which have excellent mechanical properties but high modulus and poor wear resistance. Co-Cr alloys have good mechanical properties and superior corrosion resistance, but high modulus and are difficult to machine. Ti alloys are ‘second generation’ and are used for fracture fixation and femoral hip stems. Ti alloys have excellent corrosion resistance, good biocompatibility and high mechanical strength, but poor wear resistance, poor bending ductility and come at a high cost.15 The objective of orthopaedic implants is to produce absolute stability, abolishing all interfragmentary motion. The implant material must have adequate mechanical properties. The mechanical performance characteristics of unalloyed Ti, stainless steel and Co-Cr alloys for surgical implant applications are listed in Table 1.16-18 ...
... Note: Superscript a indicates a different grade of CP Ti which often means a different oxygen content. Data are from ASTM International.16-18 ...
Stainless steel in bone surgery
1
2000
... Bone is a living tissue which undergoes constant remodelling under imposed stress. If the load supported by the implant is too large, the bone beneath will bear a reduced load and will become less dense and weaker because the stimulation and continual remodelling which maintain bone mass are absent or reduced, leading to the so-called stress-shielding phenomenon. Although Ti alloy plates (e.g. Ti-6Al-4V, CP Ti) provide less stress-shielding than stainless steel (e.g. 316L)19 because of their lower moduli,20, 21 the moduli are still much higher than that of human cortical bone (around 20 GPa).22 Thus, the stress shielding effect caused by the mismatch in the elastic modulus between human bone and Ti implants is still an issue. ...
Titanium alloys for fracture fixation implants
1
2000
... Bone is a living tissue which undergoes constant remodelling under imposed stress. If the load supported by the implant is too large, the bone beneath will bear a reduced load and will become less dense and weaker because the stimulation and continual remodelling which maintain bone mass are absent or reduced, leading to the so-called stress-shielding phenomenon. Although Ti alloy plates (e.g. Ti-6Al-4V, CP Ti) provide less stress-shielding than stainless steel (e.g. 316L)19 because of their lower moduli,20, 21 the moduli are still much higher than that of human cortical bone (around 20 GPa).22 Thus, the stress shielding effect caused by the mismatch in the elastic modulus between human bone and Ti implants is still an issue. ...
Principles of biomechanics and biomaterials in orthopaedic surgery
1
2011
... Bone is a living tissue which undergoes constant remodelling under imposed stress. If the load supported by the implant is too large, the bone beneath will bear a reduced load and will become less dense and weaker because the stimulation and continual remodelling which maintain bone mass are absent or reduced, leading to the so-called stress-shielding phenomenon. Although Ti alloy plates (e.g. Ti-6Al-4V, CP Ti) provide less stress-shielding than stainless steel (e.g. 316L)19 because of their lower moduli,20, 21 the moduli are still much higher than that of human cortical bone (around 20 GPa).22 Thus, the stress shielding effect caused by the mismatch in the elastic modulus between human bone and Ti implants is still an issue. ...
Comparison of the elastic and yield properties of human femoral trabecular and cortical bone tissue
1
2004
... Bone is a living tissue which undergoes constant remodelling under imposed stress. If the load supported by the implant is too large, the bone beneath will bear a reduced load and will become less dense and weaker because the stimulation and continual remodelling which maintain bone mass are absent or reduced, leading to the so-called stress-shielding phenomenon. Although Ti alloy plates (e.g. Ti-6Al-4V, CP Ti) provide less stress-shielding than stainless steel (e.g. 316L)19 because of their lower moduli,20, 21 the moduli are still much higher than that of human cortical bone (around 20 GPa).22 Thus, the stress shielding effect caused by the mismatch in the elastic modulus between human bone and Ti implants is still an issue. ...
Fabrication methods of porous metals for use in orthopaedic applications
1
2006
... To address this problem, alloys such as Co-Cr-Mo and Ti-6Al-4V have been manufactured as a scaffold to reduce the modulus mismatch with natural bone.23 Conventionally-sintered metals, however, are often very brittle. Other fabrication techniques (such as foaming agents or molten metal) also have some drawbacks, such as contamination, impurity phases, limited control of size and shape, and distribution of porosity.24 Noticeably, mechanical wear and corrosion are associated with a long period of implantation in the body, which results in the release of some toxic ions (Cr, Ni, Co, etc.) and triggers undesirable immune responses, consequently reducing the implant’s biocompatibility.25 Moreover, difficulty in removing locking head screws made of Ti has been reported:26 the screws cannot be removed with a normal screw driver and purpose-built devices are required. ...
Engineered porous metals for implants
1
2008
... To address this problem, alloys such as Co-Cr-Mo and Ti-6Al-4V have been manufactured as a scaffold to reduce the modulus mismatch with natural bone.23 Conventionally-sintered metals, however, are often very brittle. Other fabrication techniques (such as foaming agents or molten metal) also have some drawbacks, such as contamination, impurity phases, limited control of size and shape, and distribution of porosity.24 Noticeably, mechanical wear and corrosion are associated with a long period of implantation in the body, which results in the release of some toxic ions (Cr, Ni, Co, etc.) and triggers undesirable immune responses, consequently reducing the implant’s biocompatibility.25 Moreover, difficulty in removing locking head screws made of Ti has been reported:26 the screws cannot be removed with a normal screw driver and purpose-built devices are required. ...
Four-year study of cobalt and chromium blood levels in patients managed with two different metal-on-metal total hip replacements
1
2003
... To address this problem, alloys such as Co-Cr-Mo and Ti-6Al-4V have been manufactured as a scaffold to reduce the modulus mismatch with natural bone.23 Conventionally-sintered metals, however, are often very brittle. Other fabrication techniques (such as foaming agents or molten metal) also have some drawbacks, such as contamination, impurity phases, limited control of size and shape, and distribution of porosity.24 Noticeably, mechanical wear and corrosion are associated with a long period of implantation in the body, which results in the release of some toxic ions (Cr, Ni, Co, etc.) and triggers undesirable immune responses, consequently reducing the implant’s biocompatibility.25 Moreover, difficulty in removing locking head screws made of Ti has been reported:26 the screws cannot be removed with a normal screw driver and purpose-built devices are required. ...
Difficulties in removal of the titanium locking plate in Japan
2
2013
... To address this problem, alloys such as Co-Cr-Mo and Ti-6Al-4V have been manufactured as a scaffold to reduce the modulus mismatch with natural bone.23 Conventionally-sintered metals, however, are often very brittle. Other fabrication techniques (such as foaming agents or molten metal) also have some drawbacks, such as contamination, impurity phases, limited control of size and shape, and distribution of porosity.24 Noticeably, mechanical wear and corrosion are associated with a long period of implantation in the body, which results in the release of some toxic ions (Cr, Ni, Co, etc.) and triggers undesirable immune responses, consequently reducing the implant’s biocompatibility.25 Moreover, difficulty in removing locking head screws made of Ti has been reported:26 the screws cannot be removed with a normal screw driver and purpose-built devices are required. ...
... Note: Different values are due to differences in ethnicity, age, testing conditions, etc. NA: not applicable. Data are from Maehara et al.26-28 ...
Bone mechanical properties in healthy and diseased states
2
2018
... A more promising material for use in orthopaedic application is required and one example is biodegradable Mg alloys. Natural cortical bones have a volume density ranging from 1.0 g/cm3 to 2.1 g/cm3 and an elastic modulus ranging from 3.0 GPa to 20.0 GPa.27 Mg has a very low density of 1.74﹣2.0 g/cm3, which is significantly lower than that of Ti alloys (~4.5 g/cm3) and stainless steel (~8 g/cm3).28 Mg alloys have a relatively low elastic modulus of 41﹣45 GPa, compared with other traditional biomaterials (Ti-6Al-4V alloys: 110﹣117 GPa; 316L stainless steel: 205﹣210 GPa; Co-Cr alloys: 230 GPa).29 A comparison of Mg alloys and natural bones is shown in Table 2.27, 30, 31 Mg2+ is the fourth most abundant cation in the human body and is an essential element for the human body (the daily intake of Mg2+ for a normal adult is about 300﹣400 mg).32-34 It has been reported that moderate Mg2+ ion supplementation released directly from the prosthesis itself will bring significant benefits after implant surgery, diminishing the chance of infection.35 A number of in vivo and in vitro experiments have shown that Mg alloys have good biocompatibility.36-38 The chief attraction of Mg alloys as orthopaedic materials, however, is biodegradability. Mg alloys can be biodegraded in the human body, which can eliminate the need for a second round of surgery for implant removal. Some in vivo studies have confirmed that the degradation of Mg is harmless.37, 39, 40 ...
... 27, 30, 31 Mg2+ is the fourth most abundant cation in the human body and is an essential element for the human body (the daily intake of Mg2+ for a normal adult is about 300﹣400 mg).32-34 It has been reported that moderate Mg2+ ion supplementation released directly from the prosthesis itself will bring significant benefits after implant surgery, diminishing the chance of infection.35 A number of in vivo and in vitro experiments have shown that Mg alloys have good biocompatibility.36-38 The chief attraction of Mg alloys as orthopaedic materials, however, is biodegradability. Mg alloys can be biodegraded in the human body, which can eliminate the need for a second round of surgery for implant removal. Some in vivo studies have confirmed that the degradation of Mg is harmless.37, 39, 40 ...
Magnesium technology: metallurgy, design data, applications
2
2006
... A more promising material for use in orthopaedic application is required and one example is biodegradable Mg alloys. Natural cortical bones have a volume density ranging from 1.0 g/cm3 to 2.1 g/cm3 and an elastic modulus ranging from 3.0 GPa to 20.0 GPa.27 Mg has a very low density of 1.74﹣2.0 g/cm3, which is significantly lower than that of Ti alloys (~4.5 g/cm3) and stainless steel (~8 g/cm3).28 Mg alloys have a relatively low elastic modulus of 41﹣45 GPa, compared with other traditional biomaterials (Ti-6Al-4V alloys: 110﹣117 GPa; 316L stainless steel: 205﹣210 GPa; Co-Cr alloys: 230 GPa).29 A comparison of Mg alloys and natural bones is shown in Table 2.27, 30, 31 Mg2+ is the fourth most abundant cation in the human body and is an essential element for the human body (the daily intake of Mg2+ for a normal adult is about 300﹣400 mg).32-34 It has been reported that moderate Mg2+ ion supplementation released directly from the prosthesis itself will bring significant benefits after implant surgery, diminishing the chance of infection.35 A number of in vivo and in vitro experiments have shown that Mg alloys have good biocompatibility.36-38 The chief attraction of Mg alloys as orthopaedic materials, however, is biodegradability. Mg alloys can be biodegraded in the human body, which can eliminate the need for a second round of surgery for implant removal. Some in vivo studies have confirmed that the degradation of Mg is harmless.37, 39, 40 ...
... Note: Different values are due to differences in ethnicity, age, testing conditions, etc. NA: not applicable. Data are from Maehara et al.26-28 ...
1
2020
... A more promising material for use in orthopaedic application is required and one example is biodegradable Mg alloys. Natural cortical bones have a volume density ranging from 1.0 g/cm3 to 2.1 g/cm3 and an elastic modulus ranging from 3.0 GPa to 20.0 GPa.27 Mg has a very low density of 1.74﹣2.0 g/cm3, which is significantly lower than that of Ti alloys (~4.5 g/cm3) and stainless steel (~8 g/cm3).28 Mg alloys have a relatively low elastic modulus of 41﹣45 GPa, compared with other traditional biomaterials (Ti-6Al-4V alloys: 110﹣117 GPa; 316L stainless steel: 205﹣210 GPa; Co-Cr alloys: 230 GPa).29 A comparison of Mg alloys and natural bones is shown in Table 2.27, 30, 31 Mg2+ is the fourth most abundant cation in the human body and is an essential element for the human body (the daily intake of Mg2+ for a normal adult is about 300﹣400 mg).32-34 It has been reported that moderate Mg2+ ion supplementation released directly from the prosthesis itself will bring significant benefits after implant surgery, diminishing the chance of infection.35 A number of in vivo and in vitro experiments have shown that Mg alloys have good biocompatibility.36-38 The chief attraction of Mg alloys as orthopaedic materials, however, is biodegradability. Mg alloys can be biodegraded in the human body, which can eliminate the need for a second round of surgery for implant removal. Some in vivo studies have confirmed that the degradation of Mg is harmless.37, 39, 40 ...
Magnesium and its alloys as orthopedic biomaterials: a review
1
2006
... A more promising material for use in orthopaedic application is required and one example is biodegradable Mg alloys. Natural cortical bones have a volume density ranging from 1.0 g/cm3 to 2.1 g/cm3 and an elastic modulus ranging from 3.0 GPa to 20.0 GPa.27 Mg has a very low density of 1.74﹣2.0 g/cm3, which is significantly lower than that of Ti alloys (~4.5 g/cm3) and stainless steel (~8 g/cm3).28 Mg alloys have a relatively low elastic modulus of 41﹣45 GPa, compared with other traditional biomaterials (Ti-6Al-4V alloys: 110﹣117 GPa; 316L stainless steel: 205﹣210 GPa; Co-Cr alloys: 230 GPa).29 A comparison of Mg alloys and natural bones is shown in Table 2.27, 30, 31 Mg2+ is the fourth most abundant cation in the human body and is an essential element for the human body (the daily intake of Mg2+ for a normal adult is about 300﹣400 mg).32-34 It has been reported that moderate Mg2+ ion supplementation released directly from the prosthesis itself will bring significant benefits after implant surgery, diminishing the chance of infection.35 A number of in vivo and in vitro experiments have shown that Mg alloys have good biocompatibility.36-38 The chief attraction of Mg alloys as orthopaedic materials, however, is biodegradability. Mg alloys can be biodegraded in the human body, which can eliminate the need for a second round of surgery for implant removal. Some in vivo studies have confirmed that the degradation of Mg is harmless.37, 39, 40 ...
1
1984
... A more promising material for use in orthopaedic application is required and one example is biodegradable Mg alloys. Natural cortical bones have a volume density ranging from 1.0 g/cm3 to 2.1 g/cm3 and an elastic modulus ranging from 3.0 GPa to 20.0 GPa.27 Mg has a very low density of 1.74﹣2.0 g/cm3, which is significantly lower than that of Ti alloys (~4.5 g/cm3) and stainless steel (~8 g/cm3).28 Mg alloys have a relatively low elastic modulus of 41﹣45 GPa, compared with other traditional biomaterials (Ti-6Al-4V alloys: 110﹣117 GPa; 316L stainless steel: 205﹣210 GPa; Co-Cr alloys: 230 GPa).29 A comparison of Mg alloys and natural bones is shown in Table 2.27, 30, 31 Mg2+ is the fourth most abundant cation in the human body and is an essential element for the human body (the daily intake of Mg2+ for a normal adult is about 300﹣400 mg).32-34 It has been reported that moderate Mg2+ ion supplementation released directly from the prosthesis itself will bring significant benefits after implant surgery, diminishing the chance of infection.35 A number of in vivo and in vitro experiments have shown that Mg alloys have good biocompatibility.36-38 The chief attraction of Mg alloys as orthopaedic materials, however, is biodegradability. Mg alloys can be biodegraded in the human body, which can eliminate the need for a second round of surgery for implant removal. Some in vivo studies have confirmed that the degradation of Mg is harmless.37, 39, 40 ...
Role of magnesium in genomic stability
1
2001
... A more promising material for use in orthopaedic application is required and one example is biodegradable Mg alloys. Natural cortical bones have a volume density ranging from 1.0 g/cm3 to 2.1 g/cm3 and an elastic modulus ranging from 3.0 GPa to 20.0 GPa.27 Mg has a very low density of 1.74﹣2.0 g/cm3, which is significantly lower than that of Ti alloys (~4.5 g/cm3) and stainless steel (~8 g/cm3).28 Mg alloys have a relatively low elastic modulus of 41﹣45 GPa, compared with other traditional biomaterials (Ti-6Al-4V alloys: 110﹣117 GPa; 316L stainless steel: 205﹣210 GPa; Co-Cr alloys: 230 GPa).29 A comparison of Mg alloys and natural bones is shown in Table 2.27, 30, 31 Mg2+ is the fourth most abundant cation in the human body and is an essential element for the human body (the daily intake of Mg2+ for a normal adult is about 300﹣400 mg).32-34 It has been reported that moderate Mg2+ ion supplementation released directly from the prosthesis itself will bring significant benefits after implant surgery, diminishing the chance of infection.35 A number of in vivo and in vitro experiments have shown that Mg alloys have good biocompatibility.36-38 The chief attraction of Mg alloys as orthopaedic materials, however, is biodegradability. Mg alloys can be biodegraded in the human body, which can eliminate the need for a second round of surgery for implant removal. Some in vivo studies have confirmed that the degradation of Mg is harmless.37, 39, 40 ...
Magnesium and bone strength
2001
A possible biodegradable magnesium implant material
1
2007
... A more promising material for use in orthopaedic application is required and one example is biodegradable Mg alloys. Natural cortical bones have a volume density ranging from 1.0 g/cm3 to 2.1 g/cm3 and an elastic modulus ranging from 3.0 GPa to 20.0 GPa.27 Mg has a very low density of 1.74﹣2.0 g/cm3, which is significantly lower than that of Ti alloys (~4.5 g/cm3) and stainless steel (~8 g/cm3).28 Mg alloys have a relatively low elastic modulus of 41﹣45 GPa, compared with other traditional biomaterials (Ti-6Al-4V alloys: 110﹣117 GPa; 316L stainless steel: 205﹣210 GPa; Co-Cr alloys: 230 GPa).29 A comparison of Mg alloys and natural bones is shown in Table 2.27, 30, 31 Mg2+ is the fourth most abundant cation in the human body and is an essential element for the human body (the daily intake of Mg2+ for a normal adult is about 300﹣400 mg).32-34 It has been reported that moderate Mg2+ ion supplementation released directly from the prosthesis itself will bring significant benefits after implant surgery, diminishing the chance of infection.35 A number of in vivo and in vitro experiments have shown that Mg alloys have good biocompatibility.36-38 The chief attraction of Mg alloys as orthopaedic materials, however, is biodegradability. Mg alloys can be biodegraded in the human body, which can eliminate the need for a second round of surgery for implant removal. Some in vivo studies have confirmed that the degradation of Mg is harmless.37, 39, 40 ...
Bactericidal effect of magnesium ions over planktonic and sessile Staphylococcus epidermidis and Escherichia coli
1
2019
... A more promising material for use in orthopaedic application is required and one example is biodegradable Mg alloys. Natural cortical bones have a volume density ranging from 1.0 g/cm3 to 2.1 g/cm3 and an elastic modulus ranging from 3.0 GPa to 20.0 GPa.27 Mg has a very low density of 1.74﹣2.0 g/cm3, which is significantly lower than that of Ti alloys (~4.5 g/cm3) and stainless steel (~8 g/cm3).28 Mg alloys have a relatively low elastic modulus of 41﹣45 GPa, compared with other traditional biomaterials (Ti-6Al-4V alloys: 110﹣117 GPa; 316L stainless steel: 205﹣210 GPa; Co-Cr alloys: 230 GPa).29 A comparison of Mg alloys and natural bones is shown in Table 2.27, 30, 31 Mg2+ is the fourth most abundant cation in the human body and is an essential element for the human body (the daily intake of Mg2+ for a normal adult is about 300﹣400 mg).32-34 It has been reported that moderate Mg2+ ion supplementation released directly from the prosthesis itself will bring significant benefits after implant surgery, diminishing the chance of infection.35 A number of in vivo and in vitro experiments have shown that Mg alloys have good biocompatibility.36-38 The chief attraction of Mg alloys as orthopaedic materials, however, is biodegradability. Mg alloys can be biodegraded in the human body, which can eliminate the need for a second round of surgery for implant removal. Some in vivo studies have confirmed that the degradation of Mg is harmless.37, 39, 40 ...
In vivo corrosion behavior of Mg-Mn-Zn alloy for bone implant application
4
2007
... A more promising material for use in orthopaedic application is required and one example is biodegradable Mg alloys. Natural cortical bones have a volume density ranging from 1.0 g/cm3 to 2.1 g/cm3 and an elastic modulus ranging from 3.0 GPa to 20.0 GPa.27 Mg has a very low density of 1.74﹣2.0 g/cm3, which is significantly lower than that of Ti alloys (~4.5 g/cm3) and stainless steel (~8 g/cm3).28 Mg alloys have a relatively low elastic modulus of 41﹣45 GPa, compared with other traditional biomaterials (Ti-6Al-4V alloys: 110﹣117 GPa; 316L stainless steel: 205﹣210 GPa; Co-Cr alloys: 230 GPa).29 A comparison of Mg alloys and natural bones is shown in Table 2.27, 30, 31 Mg2+ is the fourth most abundant cation in the human body and is an essential element for the human body (the daily intake of Mg2+ for a normal adult is about 300﹣400 mg).32-34 It has been reported that moderate Mg2+ ion supplementation released directly from the prosthesis itself will bring significant benefits after implant surgery, diminishing the chance of infection.35 A number of in vivo and in vitro experiments have shown that Mg alloys have good biocompatibility.36-38 The chief attraction of Mg alloys as orthopaedic materials, however, is biodegradability. Mg alloys can be biodegraded in the human body, which can eliminate the need for a second round of surgery for implant removal. Some in vivo studies have confirmed that the degradation of Mg is harmless.37, 39, 40 ...
... The in vitro and in vivo corrosion rates of Mg-based alloys are shown in Table 5.36, 38, 39, 94, 99, 100, 103, 108-117 The in vivo corrosion rates of Mg-1.2Mn-1Zn,36 Mg-0.8Ca115 and WE43115 alloys have been reported and compared.118 These alloys have a low in vivo corrosion rate. Corrosion resistance can be modified by thermal-mechanical processing: for example, as shown in as-cast and as-extruded AZ31 alloy, as-cast and as-rolled Mg-1Zn, as-cast and as-rolled Mg-1Zr. The Mg-RE-based alloys generally show good corrosion resistance, especially after thermal-mechanical processing, for example Mg-Nd-Zn-Zr, WE43 and Mg-Gd-Zn-Zr alloys (shown in Table 5). Note that Witte et al. have reported that the in vivo (animal model) degradation of AZ91D and LAE442 alloys was very different from the in vitro corrosion.109 The major reason for the differing corrosion behaviours is the dynamic nature of the in vivo environment and the static nature of the in vitro environment. In addition, the covering of proteins on implants, the remodelling of bones and possibly a protective corrosion layer in the in vivo environment may lead to a reduced corrosion rate.109 ...
... 36 Mg-0.8Ca115 and WE43115 alloys have been reported and compared.118 These alloys have a low in vivo corrosion rate. Corrosion resistance can be modified by thermal-mechanical processing: for example, as shown in as-cast and as-extruded AZ31 alloy, as-cast and as-rolled Mg-1Zn, as-cast and as-rolled Mg-1Zr. The Mg-RE-based alloys generally show good corrosion resistance, especially after thermal-mechanical processing, for example Mg-Nd-Zn-Zr, WE43 and Mg-Gd-Zn-Zr alloys (shown in Table 5). Note that Witte et al. have reported that the in vivo (animal model) degradation of AZ91D and LAE442 alloys was very different from the in vitro corrosion.109 The major reason for the differing corrosion behaviours is the dynamic nature of the in vivo environment and the static nature of the in vitro environment. In addition, the covering of proteins on implants, the remodelling of bones and possibly a protective corrosion layer in the in vivo environment may lead to a reduced corrosion rate.109 ...
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
An update on physiological, clinical and analytical aspects
1
2000
... A more promising material for use in orthopaedic application is required and one example is biodegradable Mg alloys. Natural cortical bones have a volume density ranging from 1.0 g/cm3 to 2.1 g/cm3 and an elastic modulus ranging from 3.0 GPa to 20.0 GPa.27 Mg has a very low density of 1.74﹣2.0 g/cm3, which is significantly lower than that of Ti alloys (~4.5 g/cm3) and stainless steel (~8 g/cm3).28 Mg alloys have a relatively low elastic modulus of 41﹣45 GPa, compared with other traditional biomaterials (Ti-6Al-4V alloys: 110﹣117 GPa; 316L stainless steel: 205﹣210 GPa; Co-Cr alloys: 230 GPa).29 A comparison of Mg alloys and natural bones is shown in Table 2.27, 30, 31 Mg2+ is the fourth most abundant cation in the human body and is an essential element for the human body (the daily intake of Mg2+ for a normal adult is about 300﹣400 mg).32-34 It has been reported that moderate Mg2+ ion supplementation released directly from the prosthesis itself will bring significant benefits after implant surgery, diminishing the chance of infection.35 A number of in vivo and in vitro experiments have shown that Mg alloys have good biocompatibility.36-38 The chief attraction of Mg alloys as orthopaedic materials, however, is biodegradability. Mg alloys can be biodegraded in the human body, which can eliminate the need for a second round of surgery for implant removal. Some in vivo studies have confirmed that the degradation of Mg is harmless.37, 39, 40 ...
In vitro corrosion and biocompatibility of binary magnesium alloys
11
2009
... A more promising material for use in orthopaedic application is required and one example is biodegradable Mg alloys. Natural cortical bones have a volume density ranging from 1.0 g/cm3 to 2.1 g/cm3 and an elastic modulus ranging from 3.0 GPa to 20.0 GPa.27 Mg has a very low density of 1.74﹣2.0 g/cm3, which is significantly lower than that of Ti alloys (~4.5 g/cm3) and stainless steel (~8 g/cm3).28 Mg alloys have a relatively low elastic modulus of 41﹣45 GPa, compared with other traditional biomaterials (Ti-6Al-4V alloys: 110﹣117 GPa; 316L stainless steel: 205﹣210 GPa; Co-Cr alloys: 230 GPa).29 A comparison of Mg alloys and natural bones is shown in Table 2.27, 30, 31 Mg2+ is the fourth most abundant cation in the human body and is an essential element for the human body (the daily intake of Mg2+ for a normal adult is about 300﹣400 mg).32-34 It has been reported that moderate Mg2+ ion supplementation released directly from the prosthesis itself will bring significant benefits after implant surgery, diminishing the chance of infection.35 A number of in vivo and in vitro experiments have shown that Mg alloys have good biocompatibility.36-38 The chief attraction of Mg alloys as orthopaedic materials, however, is biodegradability. Mg alloys can be biodegraded in the human body, which can eliminate the need for a second round of surgery for implant removal. Some in vivo studies have confirmed that the degradation of Mg is harmless.37, 39, 40 ...
... Suitable alloying elements need to be tailored to design and improve the mechanical and bio-corrosion properties of biomedical Mg alloys. Table 4 shows a brief summary of the various alloying elements used in Mg biomaterials.3, 38, 69-85 Alloying elements can strengthen the Mg alloys by solid solution strengthening, precipitation hardening and grain refinement strengthening. These alloying elements must have high and temperature-dependent solubility in Mg. High solubility of an alloying element can lead to significant precipitation hardening of Mg alloys, such as Mg-Al alloys, Mg-Zn alloys and Mg-rare earth (RE) alloys. Both solid solution strengthening and precipitation strengthening improve the strength, but generally cause deterioration in the ductility of Mg alloys. However, grain refinement strengthening improves both strength and ductility. It is widely acknowledged that the refinement efficiency of the alloying elements can be determined by their growth restriction factor.86-88 The growth restriction factor is a measure of the segregation power of an element during solidification. It is calculated from binary phase diagrams and equals ΣimiC0,i (ki﹣1), where mi is the slope of the liquidus line (assumed to be straight), ki is the distribution coefficient and C0,i is the initial concentration of element i.89 If an element has a large growth restriction factor (such as Zr, Ca, Zn) this means that the growth-restricting effect on the solid-liquid interface of the new grains is strong, thus preventing new grains from growing into the melt.90 These elements segregate strongly in the melt and cause intense constitutional supercooling in a diffusion layer ahead of the advancing solid/liquid interface, consequently promoting nucleation and restricting grain growth. Therefore, these elements can significantly refine the grains, which benefits both strength and ductility. ...
... Note: Superscript a indicates that the total amount of rare earth elements (Ce, La, Nd, Pr, Y) should not exceed 4.2 mg/day. Data are from Zheng et al.3, 38, 69-85 ...
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
... The in vitro and in vivo corrosion rates of Mg-based alloys are shown in Table 5.36, 38, 39, 94, 99, 100, 103, 108-117 The in vivo corrosion rates of Mg-1.2Mn-1Zn,36 Mg-0.8Ca115 and WE43115 alloys have been reported and compared.118 These alloys have a low in vivo corrosion rate. Corrosion resistance can be modified by thermal-mechanical processing: for example, as shown in as-cast and as-extruded AZ31 alloy, as-cast and as-rolled Mg-1Zn, as-cast and as-rolled Mg-1Zr. The Mg-RE-based alloys generally show good corrosion resistance, especially after thermal-mechanical processing, for example Mg-Nd-Zn-Zr, WE43 and Mg-Gd-Zn-Zr alloys (shown in Table 5). Note that Witte et al. have reported that the in vivo (animal model) degradation of AZ91D and LAE442 alloys was very different from the in vitro corrosion.109 The major reason for the differing corrosion behaviours is the dynamic nature of the in vivo environment and the static nature of the in vitro environment. In addition, the covering of proteins on implants, the remodelling of bones and possibly a protective corrosion layer in the in vivo environment may lead to a reduced corrosion rate.109 ...
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
...
38 Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
...
38 Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
...
38 Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
...
38 Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
...
38 Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
In vivo corrosion of four magnesium alloys and the associated bone response
7
2005
... A more promising material for use in orthopaedic application is required and one example is biodegradable Mg alloys. Natural cortical bones have a volume density ranging from 1.0 g/cm3 to 2.1 g/cm3 and an elastic modulus ranging from 3.0 GPa to 20.0 GPa.27 Mg has a very low density of 1.74﹣2.0 g/cm3, which is significantly lower than that of Ti alloys (~4.5 g/cm3) and stainless steel (~8 g/cm3).28 Mg alloys have a relatively low elastic modulus of 41﹣45 GPa, compared with other traditional biomaterials (Ti-6Al-4V alloys: 110﹣117 GPa; 316L stainless steel: 205﹣210 GPa; Co-Cr alloys: 230 GPa).29 A comparison of Mg alloys and natural bones is shown in Table 2.27, 30, 31 Mg2+ is the fourth most abundant cation in the human body and is an essential element for the human body (the daily intake of Mg2+ for a normal adult is about 300﹣400 mg).32-34 It has been reported that moderate Mg2+ ion supplementation released directly from the prosthesis itself will bring significant benefits after implant surgery, diminishing the chance of infection.35 A number of in vivo and in vitro experiments have shown that Mg alloys have good biocompatibility.36-38 The chief attraction of Mg alloys as orthopaedic materials, however, is biodegradability. Mg alloys can be biodegraded in the human body, which can eliminate the need for a second round of surgery for implant removal. Some in vivo studies have confirmed that the degradation of Mg is harmless.37, 39, 40 ...
... The in vitro and in vivo corrosion rates of Mg-based alloys are shown in Table 5.36, 38, 39, 94, 99, 100, 103, 108-117 The in vivo corrosion rates of Mg-1.2Mn-1Zn,36 Mg-0.8Ca115 and WE43115 alloys have been reported and compared.118 These alloys have a low in vivo corrosion rate. Corrosion resistance can be modified by thermal-mechanical processing: for example, as shown in as-cast and as-extruded AZ31 alloy, as-cast and as-rolled Mg-1Zn, as-cast and as-rolled Mg-1Zr. The Mg-RE-based alloys generally show good corrosion resistance, especially after thermal-mechanical processing, for example Mg-Nd-Zn-Zr, WE43 and Mg-Gd-Zn-Zr alloys (shown in Table 5). Note that Witte et al. have reported that the in vivo (animal model) degradation of AZ91D and LAE442 alloys was very different from the in vitro corrosion.109 The major reason for the differing corrosion behaviours is the dynamic nature of the in vivo environment and the static nature of the in vitro environment. In addition, the covering of proteins on implants, the remodelling of bones and possibly a protective corrosion layer in the in vivo environment may lead to a reduced corrosion rate.109 ...
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
...
39,
94 Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
... The in vivo assessment of the compatibility of biomaterials and medical devices with tissue is important for the development and implementation of implants for human use. Many in vivo studies have been conducted to understand the degradation process and the associated mechanisms. Animal models are adopted in order to determine the response to the biomaterials or medical devices, such as the interactions of various cell types with the implants, endocrine factors acting on cells around the implant and interactions with blood-borne cells and proteins. In vivo studies have mainly been performed on small animals, such as guinea pigs, rats and rabbits. Heublein et al.191 investigated a cardiovascular stent (AE21 alloy) in domestic pigs. There is a report describing the implantation of Mg chips into the spines of sheep.192 The first comprehensive in vivo study on Mg alloys was carried out by Witte et al.39 on four different Mg alloys (AZ31, AZ91, WE43 and LAE442), and these four Mg alloys were implanted into the femurs of guinea pigs. A newly-formed mineral phase was observed on the surface of the Mg implants during implant degradation, which stained with calcein green under fluorescent light (Figure 8A).39 The in vivo bio-corrosion morphology of the remaining Mg alloy in the guinea pig femora is shown in Figures 8B and C.109 It can be seen that the AZ91D rod was almost completely corroded, while the LAE442 rod was corroded more uniformly. Both of these Mg alloys exhibited good biocompatibility as evidenced by the direct contact with newly-formed bone. ...
... 39 The in vivo bio-corrosion morphology of the remaining Mg alloy in the guinea pig femora is shown in Figures 8B and C.109 It can be seen that the AZ91D rod was almost completely corroded, while the LAE442 rod was corroded more uniformly. Both of these Mg alloys exhibited good biocompatibility as evidenced by the direct contact with newly-formed bone. ...
...
39,
109 Copyright 2005 & 2006, with permission from Elsevier Ltd.
Recently, some in vivo studies were carried out on large animal models. A goat was used to study the clinical capability of osteosynthesis of a lean Mg alloy (Mg-0.45Zn-0.45Ca) screw.51 In vivo transformation experiments on high-purity weight-bearing Mg screws were also carried out on goats.193 Small animals (rats) and large animals (sheep) have been used to compare the biodegradation rate, bone formation and in-growth of bone into Mg-0.45Zn-0.45Ca implants.194 A pig model was designed to evaluate the in vivo performance of a Mg-4Zn-0.1Sr anastomosis ring.195 A miniature pig has been employed to perform pre-clinical testing of human-sized Mg implants at multiple implantation sites.196 ...
Biodegradable magnesium scaffolds: Part 1: appropriate inflammatory response
3
2007
... A more promising material for use in orthopaedic application is required and one example is biodegradable Mg alloys. Natural cortical bones have a volume density ranging from 1.0 g/cm3 to 2.1 g/cm3 and an elastic modulus ranging from 3.0 GPa to 20.0 GPa.27 Mg has a very low density of 1.74﹣2.0 g/cm3, which is significantly lower than that of Ti alloys (~4.5 g/cm3) and stainless steel (~8 g/cm3).28 Mg alloys have a relatively low elastic modulus of 41﹣45 GPa, compared with other traditional biomaterials (Ti-6Al-4V alloys: 110﹣117 GPa; 316L stainless steel: 205﹣210 GPa; Co-Cr alloys: 230 GPa).29 A comparison of Mg alloys and natural bones is shown in Table 2.27, 30, 31 Mg2+ is the fourth most abundant cation in the human body and is an essential element for the human body (the daily intake of Mg2+ for a normal adult is about 300﹣400 mg).32-34 It has been reported that moderate Mg2+ ion supplementation released directly from the prosthesis itself will bring significant benefits after implant surgery, diminishing the chance of infection.35 A number of in vivo and in vitro experiments have shown that Mg alloys have good biocompatibility.36-38 The chief attraction of Mg alloys as orthopaedic materials, however, is biodegradability. Mg alloys can be biodegraded in the human body, which can eliminate the need for a second round of surgery for implant removal. Some in vivo studies have confirmed that the degradation of Mg is harmless.37, 39, 40 ...
... Powder metallurgy, laser additive manufacturing, the metal/gas eutectic unidirectional solidification process and the negative salt-pattern moulding method have all been used to produce a porous Mg scaffold. Porous WE43 scaffolds were fabricated by laser-powder bed fusion and their in vitro performance was first reported by Li et al.165 The diamond lattice was adopted to construct a porous scaffold cylinder with a diameter of 10 mm and a height of 11.2 mm, as shown in Figure 6A. Geng et al.166 reported that the pore size and porosity (48%) of a honeycomb-structured Mg scaffold (shown in Figure 6B167) can be controlled by the laser perforation technique. Witte et al. reported an open porous AZ91 alloy scaffold with porosity ranging from 72% to 76% and a pore size varying between 10 and 1000 µm, which was created by infiltrating molten Mg into a NaCl preform and then washing out the salt preform in NaOH solution.40, 168 Gu et al.169 produced a lotus-type porous pure Mg using a metal/gas eutectic unidirectional solidification method, which showed a slower decay in compressive YS than that of pure Mg during immersion in simulated body fluid. ...
...
40 Copyright 2017, with permission from Acta Materialia Inc. (B) Honeycomb-structured magnesium scaffold produced by laser perforation. Reprinted from Tan et al.
167 Copyright IOP Publishing. Reproduced with permission. All rights reserved. Scale bars: 1 mm.
It has been stated that the scaffold structure provides three-dimensional space for cell adhesion and ingrowth, giving good biocompatibility.170 More importantly, the laser additive manufacturing technology used to build the scaffold has significant advantages in the fabrication of complex porous structures and customised implants addressing specific clinical needs. However, the pore structure (including pore size, shape, connectivity, etc.) needs to be carefully controlled, because this is one of the key factors determining the mechanical properties of porous Mg. ...
Mechanical characterization of biodegradable implants
1
1992
... In order to replace permanent metallic implants for orthopaedic applications, Mg alloys need to target both mechanical requirements and an appropriate degradation rate. Figure 3 shows a schematic of the optimal relationship between provision of mechanical support and biodegradation behaviour. Initially, it is essential that the implants are strong enough to provide sustained fixation, support the injury and carry the load to give adequate time for the damaged bone tissues to heal. The implant should gradually and slowly degrade and transfer the load to the bone over time.41 Before the injury heals, the implant has constantly to sustain the injury and provide mechanical support until the tissue regains sufficient mechanical strength. A period of 3﹣4 months is generally required for new bone formation and recovery of most of the bone’s original strength.42 The different healing periods relate to the different ages of the patients. ...
Principles of fracture management
2
2007
... In order to replace permanent metallic implants for orthopaedic applications, Mg alloys need to target both mechanical requirements and an appropriate degradation rate. Figure 3 shows a schematic of the optimal relationship between provision of mechanical support and biodegradation behaviour. Initially, it is essential that the implants are strong enough to provide sustained fixation, support the injury and carry the load to give adequate time for the damaged bone tissues to heal. The implant should gradually and slowly degrade and transfer the load to the bone over time.41 Before the injury heals, the implant has constantly to sustain the injury and provide mechanical support until the tissue regains sufficient mechanical strength. A period of 3﹣4 months is generally required for new bone formation and recovery of most of the bone’s original strength.42 The different healing periods relate to the different ages of the patients. ...
... 2) A hydrogen evolution method has been developed by Song et al.182 based on the collection of hydrogen gas during degradation of Mg in aqueous solutions. The hydrogen evolution measurement is currently very popular and is widely accepted by many researchers.10, 42, 59, 106, 107, 178-181 The mechanism of this measurement is simple and easy to understand, and is based on the reaction below: ...
Insight in applications, manufacturing and corrosion behaviour of magnesium and its alloys - A review
1
2020
... For load-bearing applications, the implant material has to have suitable mechanical properties to withstand various biomechanical forces. The mechanical properties of interest for the implant are elastic modulus, yield strength, ultimate tensile strength and ductility. To bend fixtures to fit properly requires sufficient ductility.43 Materials with higher elastic modulus can absorb more energy and hold their shape better, and are therefore less likely to ‘cut’ into the bone.44 In addition, although fast corrosion kinetics can be generally beneficial in biodegradable alloys, there is a balance to be struck and Mg alloys can have a significant problem if the corrosion rate is too high. Current Mg alloys degrade too quickly in the human body and lose function before the tissue heals. ...
1
2017
... For load-bearing applications, the implant material has to have suitable mechanical properties to withstand various biomechanical forces. The mechanical properties of interest for the implant are elastic modulus, yield strength, ultimate tensile strength and ductility. To bend fixtures to fit properly requires sufficient ductility.43 Materials with higher elastic modulus can absorb more energy and hold their shape better, and are therefore less likely to ‘cut’ into the bone.44 In addition, although fast corrosion kinetics can be generally beneficial in biodegradable alloys, there is a balance to be struck and Mg alloys can have a significant problem if the corrosion rate is too high. Current Mg alloys degrade too quickly in the human body and lose function before the tissue heals. ...
Microstructure and degradation behaviour of Mg-Zn(-Ca) alloys
5
2014
... Obviously, the hydrolysis reaction consumes H2O and produces H+, and thus reduces the pH value in the solution. The precipitation of Mg(OH)2 and stabilisation of the passive film tend to occur because of pH increases due to the cathodic reaction. Alkalisation of the solution occurs over time, which is caused by the cathodic reaction and the balance between the anodic and cathodic reactions. Each Mg2+ formed produces two OH- and generates one H+. Therefore, the overall reaction results in a pH increase, which must be paid attention to when monitoring the biodegradation rate. Figure 4 illustrates the corrosion mechanism of Mg in an aqueous environment.45 The processes of equations (1-4) are vividly demonstrated in Figure 4A. The dissolution of Mg and the formation of hydrogen and Mg hydroxide are the main features. The aggressive ion Cl- reacts with Mg(OH)2 and forms more soluble MgCl2 (equation (5)). ...
...
45 (A) The dissolution of magnesium via the anodic reaction. The cathodic reaction increases the pH and produces H
2, while hydrolysis reduces the pH. Intermetallic particles act as cathodic sites and consume the electrons produced by the anodic reaction. (B) Chloride ions in the solution attack and dissolve the Mg(OH)
2 film.
Further corrosion of Mg is promoted by the dissolution of Mg(OH)2 due to the disappearance of the protected areas.46 Cl-catalyses the dissolution of Mg and directly produces MgCl2, exposing the bare Mg to the solution47, 48 (Figure 4B). ...
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
... 45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
...
45 (B) Reprinted from Chen et al.
84 Copyright 2014, with permission from Acta Materialia Inc.
The in vitro and in vivo corrosion rates of Mg-based alloys are shown in Table 5.36, 38, 39, 94, 99, 100, 103, 108-117 The in vivo corrosion rates of Mg-1.2Mn-1Zn,36 Mg-0.8Ca115 and WE43115 alloys have been reported and compared.118 These alloys have a low in vivo corrosion rate. Corrosion resistance can be modified by thermal-mechanical processing: for example, as shown in as-cast and as-extruded AZ31 alloy, as-cast and as-rolled Mg-1Zn, as-cast and as-rolled Mg-1Zr. The Mg-RE-based alloys generally show good corrosion resistance, especially after thermal-mechanical processing, for example Mg-Nd-Zn-Zr, WE43 and Mg-Gd-Zn-Zr alloys (shown in Table 5). Note that Witte et al. have reported that the in vivo (animal model) degradation of AZ91D and LAE442 alloys was very different from the in vitro corrosion.109 The major reason for the differing corrosion behaviours is the dynamic nature of the in vivo environment and the static nature of the in vitro environment. In addition, the covering of proteins on implants, the remodelling of bones and possibly a protective corrosion layer in the in vivo environment may lead to a reduced corrosion rate.109 ...
Understanding magnesium corrosion—a framework for improved alloy performance
2
2003
... Further corrosion of Mg is promoted by the dissolution of Mg(OH)2 due to the disappearance of the protected areas.46 Cl-catalyses the dissolution of Mg and directly produces MgCl2, exposing the bare Mg to the solution47, 48 (Figure 4B). ...
... Second phases have a significant impact on the performance of Mg alloys.128, 129 A homogenous microstructure is desirable, because a difference in corrosion potential between the α-Mg and the second phase causes micro-galvanic corrosion. In AZ alloys, the Mg17Al12 phase (﹣1.20 V) is nobler than the α-Mg matrix (﹣1.65 V)46 and therefore acts as a cathode and aggravates the corrosion of Mg.91, 130 Some researchers have proposed that the Mg17Al12 phase can act as a corrosion barrier and have a positive effect on corrosion resistance.128, 129, 131 The fraction and distribution of Mg17Al12 phases are important factors in determining which effect dominates. A finely- and continuously-distributed β-phase serves as a corrosion barrier and inhibits corrosion;119 otherwise, the β-phase promotes corrosion. Song et al.126 proposed that more continuous second phases can benefit the corrosion resistance of the Mg-RE-Zr alloy (MEZ alloy). The morphology of the second phase also affects the corrosion behaviour of Mg alloys. Srinivasan et al.132 reported that Mg with a coarse Chinese script Mg2Si phase shows a weaker corrosion performance than that with evenly-distributed polygonal-shaped Mg2Si phases. The reduction and refinement of Mg2Si phases also lead to better corrosion behaviour of Mg-Si(-Ca) alloys.91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
Studies on the influence of chloride ion and pH on the corrosion and electrochemical behaviour of AZ91D magnesium alloy
1
2000
... Further corrosion of Mg is promoted by the dissolution of Mg(OH)2 due to the disappearance of the protected areas.46 Cl-catalyses the dissolution of Mg and directly produces MgCl2, exposing the bare Mg to the solution47, 48 (Figure 4B). ...
Evaluation of microstructural effects on corrosion behaviour of AZ91D magnesium alloy
2
2000
... Further corrosion of Mg is promoted by the dissolution of Mg(OH)2 due to the disappearance of the protected areas.46 Cl-catalyses the dissolution of Mg and directly produces MgCl2, exposing the bare Mg to the solution47, 48 (Figure 4B). ...
... The corrosion behaviour of Mg alloys is closely related to their grain size. Grain refinement is an effective way to improve the corrosion performance of Mg alloys.48, 119-122 For example, Lu et al.111 found that the bio-corrosion rate of Mg-3Zn-0.3Ca is a function of grain size and the volume fraction of secondary phase. Birbilis et al.122 proposed that the corrosion rate increases as the logarithm of average grain size increases in pure Mg. Ralston et al.123 also described a relationship between corrosion rate and grain size: icorr=(A)+(B)·GS﹣0.5 (where A is a constant and a function of the environment; B is a material constant and is determined by the composition and impurity level of the material; GS is grain size and icorr is the corrosion rate). Corrosion resistance can be linearly enhanced by reducing the grain size. It has been reported that the reason why grain refinement causes a decreased corrosion rate is because of the improved passive film. A high grain boundary density promotes a better oxide film conduction rate on surfaces with low to passive corrosion rates and therefore a fine grain structure is more corrosion resistant.124, 125 Song and StJohn 126 indicated that the skin of the die-cast AZ91D alloy exhibits better corrosion performance than the interior, because of the more continuous Mg17Al12 phase formed around finer α-Mg grains. If the grains are small and the volume fraction of the Mg17Al12 phase is not too low, then the Mg17Al12 phase forms continuously like a net, and is difficult to undercut because corrosion development cannot easily progress through numerous Mg17Al12 precipitates. The Mg17Al12 phase is exposed and the α-Mg phase corrodes preferentially. Eventually, the final surface of the sample has large amounts of Mg17Al12 which are more corrosion resistant than the α-Mg phase, thus the corrosion resistance is enhanced.91, 127 ...
Magnesium alloys for temporary implants in osteosynthesis: in vivo studies of their degradation and interaction with bone
1
2012
... Following the reaction of Mg in the physiological environment, it must be mentioned that hydrogen evolves during the reaction according to the cathodic reaction. Gas cavities composed of generated hydrogen have been observed around Mg alloy implants because of insufficient diffusion.49 The formation of these gas pockets happens during the early implantation stage (7-30 days); the gas is then gradually absorbed by the surrounding tissue.50 It has been reported that gas formation does not have any negative effects on bone healing.51 However, the rapid corrosion of Mg causes the quick formation of gas cavities and subcutaneous bubbles, which may reduce its mechanical strength. Thus, in order to slow hydrogen generation, the degradation rate of Mg-based alloys must be carefully controlled. ...
In vitro studies of biomedical magnesium alloys in a simulated physiological environment: a review
1
2011
... Following the reaction of Mg in the physiological environment, it must be mentioned that hydrogen evolves during the reaction according to the cathodic reaction. Gas cavities composed of generated hydrogen have been observed around Mg alloy implants because of insufficient diffusion.49 The formation of these gas pockets happens during the early implantation stage (7-30 days); the gas is then gradually absorbed by the surrounding tissue.50 It has been reported that gas formation does not have any negative effects on bone healing.51 However, the rapid corrosion of Mg causes the quick formation of gas cavities and subcutaneous bubbles, which may reduce its mechanical strength. Thus, in order to slow hydrogen generation, the degradation rate of Mg-based alloys must be carefully controlled. ...
A lean magnesium-zinc-calcium alloy ZX00 used for bone fracture stabilization in a large growing-animal model
2
2020
... Following the reaction of Mg in the physiological environment, it must be mentioned that hydrogen evolves during the reaction according to the cathodic reaction. Gas cavities composed of generated hydrogen have been observed around Mg alloy implants because of insufficient diffusion.49 The formation of these gas pockets happens during the early implantation stage (7-30 days); the gas is then gradually absorbed by the surrounding tissue.50 It has been reported that gas formation does not have any negative effects on bone healing.51 However, the rapid corrosion of Mg causes the quick formation of gas cavities and subcutaneous bubbles, which may reduce its mechanical strength. Thus, in order to slow hydrogen generation, the degradation rate of Mg-based alloys must be carefully controlled. ...
... Recently, some in vivo studies were carried out on large animal models. A goat was used to study the clinical capability of osteosynthesis of a lean Mg alloy (Mg-0.45Zn-0.45Ca) screw.51 In vivo transformation experiments on high-purity weight-bearing Mg screws were also carried out on goats.193 Small animals (rats) and large animals (sheep) have been used to compare the biodegradation rate, bone formation and in-growth of bone into Mg-0.45Zn-0.45Ca implants.194 A pig model was designed to evaluate the in vivo performance of a Mg-4Zn-0.1Sr anastomosis ring.195 A miniature pig has been employed to perform pre-clinical testing of human-sized Mg implants at multiple implantation sites.196 ...
Magnesium basics
2
2012
... Mg is a nutrient that the body needs to stay healthy and is important for many processes. Mg is primarily found within the cells and is a cofactor in more than 300 enzymatic reactions, which are essential for the human body.52 The presence of Mg is vital for transmission and storage of energy to be used by cells.53 It also has a central role in cell growth and the structure and permeability of their membranes.52, 54 It has been reported that Mg2+ ions are able to aid the growth of bone marrow cells through the enhancement of bone morphogenetic protein receptor recognition and Smad signalling pathways.55 The mitogen-activated protein kinase/extracellular signal-regulated kinase pathway is one of the signalling pathways which controls the osteogenic differentiation of stem cells, and Mg2+ can selectively activate the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway.56 The biphasic mode of Mg2+ in bone repair has been recently reported by Qiao et al.57 Mg-induced osteogenesis has been observed, suggesting the therapeutic potential of Mg2+ in orthopaedics.58-60 In addition, Mg2+ ions affect the seeded calcium phosphate crystallisation rate and subsequent hydroxyapatite growth.61 The total body stores of Mg are between 21 g and 28 g in the average 70 kg adult. Normal serum usually has a Mg range of 1.7 mg/dL to 2.5 mg/dL. Most of the body’s Mg is in the skeletal bone mass, which accounts for more than 50% of the body’s stores. The remainder is located in soft tissues, of which only 0.3% is located extracellularly. Of the total Mg consumed, approximately 30% to 50% is absorbed.62 Too much Mg from food does not pose a health risk because the kidneys eliminate excess amounts via the urine.63 However, a very high dose of Mg via, for example, dietary supplements or medications can result in diarrhoea that can be accompanied by nausea and abdominal cramping.64 The daily intake allowances of Mg are summarised in Table 3.65 ...
... 52, 54 It has been reported that Mg2+ ions are able to aid the growth of bone marrow cells through the enhancement of bone morphogenetic protein receptor recognition and Smad signalling pathways.55 The mitogen-activated protein kinase/extracellular signal-regulated kinase pathway is one of the signalling pathways which controls the osteogenic differentiation of stem cells, and Mg2+ can selectively activate the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway.56 The biphasic mode of Mg2+ in bone repair has been recently reported by Qiao et al.57 Mg-induced osteogenesis has been observed, suggesting the therapeutic potential of Mg2+ in orthopaedics.58-60 In addition, Mg2+ ions affect the seeded calcium phosphate crystallisation rate and subsequent hydroxyapatite growth.61 The total body stores of Mg are between 21 g and 28 g in the average 70 kg adult. Normal serum usually has a Mg range of 1.7 mg/dL to 2.5 mg/dL. Most of the body’s Mg is in the skeletal bone mass, which accounts for more than 50% of the body’s stores. The remainder is located in soft tissues, of which only 0.3% is located extracellularly. Of the total Mg consumed, approximately 30% to 50% is absorbed.62 Too much Mg from food does not pose a health risk because the kidneys eliminate excess amounts via the urine.63 However, a very high dose of Mg via, for example, dietary supplements or medications can result in diarrhoea that can be accompanied by nausea and abdominal cramping.64 The daily intake allowances of Mg are summarised in Table 3.65 ...
The role of magnesium in different inflammatory diseases
1
2019
... Mg is a nutrient that the body needs to stay healthy and is important for many processes. Mg is primarily found within the cells and is a cofactor in more than 300 enzymatic reactions, which are essential for the human body.52 The presence of Mg is vital for transmission and storage of energy to be used by cells.53 It also has a central role in cell growth and the structure and permeability of their membranes.52, 54 It has been reported that Mg2+ ions are able to aid the growth of bone marrow cells through the enhancement of bone morphogenetic protein receptor recognition and Smad signalling pathways.55 The mitogen-activated protein kinase/extracellular signal-regulated kinase pathway is one of the signalling pathways which controls the osteogenic differentiation of stem cells, and Mg2+ can selectively activate the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway.56 The biphasic mode of Mg2+ in bone repair has been recently reported by Qiao et al.57 Mg-induced osteogenesis has been observed, suggesting the therapeutic potential of Mg2+ in orthopaedics.58-60 In addition, Mg2+ ions affect the seeded calcium phosphate crystallisation rate and subsequent hydroxyapatite growth.61 The total body stores of Mg are between 21 g and 28 g in the average 70 kg adult. Normal serum usually has a Mg range of 1.7 mg/dL to 2.5 mg/dL. Most of the body’s Mg is in the skeletal bone mass, which accounts for more than 50% of the body’s stores. The remainder is located in soft tissues, of which only 0.3% is located extracellularly. Of the total Mg consumed, approximately 30% to 50% is absorbed.62 Too much Mg from food does not pose a health risk because the kidneys eliminate excess amounts via the urine.63 However, a very high dose of Mg via, for example, dietary supplements or medications can result in diarrhoea that can be accompanied by nausea and abdominal cramping.64 The daily intake allowances of Mg are summarised in Table 3.65 ...
Magnesium deficiency: pathophysiologic and clinical overview
1
1994
... Mg is a nutrient that the body needs to stay healthy and is important for many processes. Mg is primarily found within the cells and is a cofactor in more than 300 enzymatic reactions, which are essential for the human body.52 The presence of Mg is vital for transmission and storage of energy to be used by cells.53 It also has a central role in cell growth and the structure and permeability of their membranes.52, 54 It has been reported that Mg2+ ions are able to aid the growth of bone marrow cells through the enhancement of bone morphogenetic protein receptor recognition and Smad signalling pathways.55 The mitogen-activated protein kinase/extracellular signal-regulated kinase pathway is one of the signalling pathways which controls the osteogenic differentiation of stem cells, and Mg2+ can selectively activate the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway.56 The biphasic mode of Mg2+ in bone repair has been recently reported by Qiao et al.57 Mg-induced osteogenesis has been observed, suggesting the therapeutic potential of Mg2+ in orthopaedics.58-60 In addition, Mg2+ ions affect the seeded calcium phosphate crystallisation rate and subsequent hydroxyapatite growth.61 The total body stores of Mg are between 21 g and 28 g in the average 70 kg adult. Normal serum usually has a Mg range of 1.7 mg/dL to 2.5 mg/dL. Most of the body’s Mg is in the skeletal bone mass, which accounts for more than 50% of the body’s stores. The remainder is located in soft tissues, of which only 0.3% is located extracellularly. Of the total Mg consumed, approximately 30% to 50% is absorbed.62 Too much Mg from food does not pose a health risk because the kidneys eliminate excess amounts via the urine.63 However, a very high dose of Mg via, for example, dietary supplements or medications can result in diarrhoea that can be accompanied by nausea and abdominal cramping.64 The daily intake allowances of Mg are summarised in Table 3.65 ...
Magnesium modification up-regulates the bioactivity of bone morphogenetic protein-2 upon calcium phosphate cement via enhanced BMP receptor recognition and Smad signaling pathway
1
2016
... Mg is a nutrient that the body needs to stay healthy and is important for many processes. Mg is primarily found within the cells and is a cofactor in more than 300 enzymatic reactions, which are essential for the human body.52 The presence of Mg is vital for transmission and storage of energy to be used by cells.53 It also has a central role in cell growth and the structure and permeability of their membranes.52, 54 It has been reported that Mg2+ ions are able to aid the growth of bone marrow cells through the enhancement of bone morphogenetic protein receptor recognition and Smad signalling pathways.55 The mitogen-activated protein kinase/extracellular signal-regulated kinase pathway is one of the signalling pathways which controls the osteogenic differentiation of stem cells, and Mg2+ can selectively activate the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway.56 The biphasic mode of Mg2+ in bone repair has been recently reported by Qiao et al.57 Mg-induced osteogenesis has been observed, suggesting the therapeutic potential of Mg2+ in orthopaedics.58-60 In addition, Mg2+ ions affect the seeded calcium phosphate crystallisation rate and subsequent hydroxyapatite growth.61 The total body stores of Mg are between 21 g and 28 g in the average 70 kg adult. Normal serum usually has a Mg range of 1.7 mg/dL to 2.5 mg/dL. Most of the body’s Mg is in the skeletal bone mass, which accounts for more than 50% of the body’s stores. The remainder is located in soft tissues, of which only 0.3% is located extracellularly. Of the total Mg consumed, approximately 30% to 50% is absorbed.62 Too much Mg from food does not pose a health risk because the kidneys eliminate excess amounts via the urine.63 However, a very high dose of Mg via, for example, dietary supplements or medications can result in diarrhoea that can be accompanied by nausea and abdominal cramping.64 The daily intake allowances of Mg are summarised in Table 3.65 ...
Magnesium-based biomaterials as emerging agents for bone repair and regeneration: from mechanism to application
1
2021
... Mg is a nutrient that the body needs to stay healthy and is important for many processes. Mg is primarily found within the cells and is a cofactor in more than 300 enzymatic reactions, which are essential for the human body.52 The presence of Mg is vital for transmission and storage of energy to be used by cells.53 It also has a central role in cell growth and the structure and permeability of their membranes.52, 54 It has been reported that Mg2+ ions are able to aid the growth of bone marrow cells through the enhancement of bone morphogenetic protein receptor recognition and Smad signalling pathways.55 The mitogen-activated protein kinase/extracellular signal-regulated kinase pathway is one of the signalling pathways which controls the osteogenic differentiation of stem cells, and Mg2+ can selectively activate the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway.56 The biphasic mode of Mg2+ in bone repair has been recently reported by Qiao et al.57 Mg-induced osteogenesis has been observed, suggesting the therapeutic potential of Mg2+ in orthopaedics.58-60 In addition, Mg2+ ions affect the seeded calcium phosphate crystallisation rate and subsequent hydroxyapatite growth.61 The total body stores of Mg are between 21 g and 28 g in the average 70 kg adult. Normal serum usually has a Mg range of 1.7 mg/dL to 2.5 mg/dL. Most of the body’s Mg is in the skeletal bone mass, which accounts for more than 50% of the body’s stores. The remainder is located in soft tissues, of which only 0.3% is located extracellularly. Of the total Mg consumed, approximately 30% to 50% is absorbed.62 Too much Mg from food does not pose a health risk because the kidneys eliminate excess amounts via the urine.63 However, a very high dose of Mg via, for example, dietary supplements or medications can result in diarrhoea that can be accompanied by nausea and abdominal cramping.64 The daily intake allowances of Mg are summarised in Table 3.65 ...
TRPM7 kinase-mediated immunomodulation in macrophage plays a central role in magnesium ion-induced bone regeneration
1
2021
... Mg is a nutrient that the body needs to stay healthy and is important for many processes. Mg is primarily found within the cells and is a cofactor in more than 300 enzymatic reactions, which are essential for the human body.52 The presence of Mg is vital for transmission and storage of energy to be used by cells.53 It also has a central role in cell growth and the structure and permeability of their membranes.52, 54 It has been reported that Mg2+ ions are able to aid the growth of bone marrow cells through the enhancement of bone morphogenetic protein receptor recognition and Smad signalling pathways.55 The mitogen-activated protein kinase/extracellular signal-regulated kinase pathway is one of the signalling pathways which controls the osteogenic differentiation of stem cells, and Mg2+ can selectively activate the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway.56 The biphasic mode of Mg2+ in bone repair has been recently reported by Qiao et al.57 Mg-induced osteogenesis has been observed, suggesting the therapeutic potential of Mg2+ in orthopaedics.58-60 In addition, Mg2+ ions affect the seeded calcium phosphate crystallisation rate and subsequent hydroxyapatite growth.61 The total body stores of Mg are between 21 g and 28 g in the average 70 kg adult. Normal serum usually has a Mg range of 1.7 mg/dL to 2.5 mg/dL. Most of the body’s Mg is in the skeletal bone mass, which accounts for more than 50% of the body’s stores. The remainder is located in soft tissues, of which only 0.3% is located extracellularly. Of the total Mg consumed, approximately 30% to 50% is absorbed.62 Too much Mg from food does not pose a health risk because the kidneys eliminate excess amounts via the urine.63 However, a very high dose of Mg via, for example, dietary supplements or medications can result in diarrhoea that can be accompanied by nausea and abdominal cramping.64 The daily intake allowances of Mg are summarised in Table 3.65 ...
Implant-derived magnesium induces local neuronal production of CGRP to improve bone-fracture healing in rats
1
2016
... Mg is a nutrient that the body needs to stay healthy and is important for many processes. Mg is primarily found within the cells and is a cofactor in more than 300 enzymatic reactions, which are essential for the human body.52 The presence of Mg is vital for transmission and storage of energy to be used by cells.53 It also has a central role in cell growth and the structure and permeability of their membranes.52, 54 It has been reported that Mg2+ ions are able to aid the growth of bone marrow cells through the enhancement of bone morphogenetic protein receptor recognition and Smad signalling pathways.55 The mitogen-activated protein kinase/extracellular signal-regulated kinase pathway is one of the signalling pathways which controls the osteogenic differentiation of stem cells, and Mg2+ can selectively activate the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway.56 The biphasic mode of Mg2+ in bone repair has been recently reported by Qiao et al.57 Mg-induced osteogenesis has been observed, suggesting the therapeutic potential of Mg2+ in orthopaedics.58-60 In addition, Mg2+ ions affect the seeded calcium phosphate crystallisation rate and subsequent hydroxyapatite growth.61 The total body stores of Mg are between 21 g and 28 g in the average 70 kg adult. Normal serum usually has a Mg range of 1.7 mg/dL to 2.5 mg/dL. Most of the body’s Mg is in the skeletal bone mass, which accounts for more than 50% of the body’s stores. The remainder is located in soft tissues, of which only 0.3% is located extracellularly. Of the total Mg consumed, approximately 30% to 50% is absorbed.62 Too much Mg from food does not pose a health risk because the kidneys eliminate excess amounts via the urine.63 However, a very high dose of Mg via, for example, dietary supplements or medications can result in diarrhoea that can be accompanied by nausea and abdominal cramping.64 The daily intake allowances of Mg are summarised in Table 3.65 ...
Osteogenesis, angiogenesis and immune response of Mg-Al layered double hydroxide coating on pure Mg
1
2021
... 2) A hydrogen evolution method has been developed by Song et al.182 based on the collection of hydrogen gas during degradation of Mg in aqueous solutions. The hydrogen evolution measurement is currently very popular and is widely accepted by many researchers.10, 42, 59, 106, 107, 178-181 The mechanism of this measurement is simple and easy to understand, and is based on the reaction below: ...
Magnesium ion stimulation of bone marrow stromal cells enhances osteogenic activity, simulating the effect of magnesium alloy degradation
1
2014
... Mg is a nutrient that the body needs to stay healthy and is important for many processes. Mg is primarily found within the cells and is a cofactor in more than 300 enzymatic reactions, which are essential for the human body.52 The presence of Mg is vital for transmission and storage of energy to be used by cells.53 It also has a central role in cell growth and the structure and permeability of their membranes.52, 54 It has been reported that Mg2+ ions are able to aid the growth of bone marrow cells through the enhancement of bone morphogenetic protein receptor recognition and Smad signalling pathways.55 The mitogen-activated protein kinase/extracellular signal-regulated kinase pathway is one of the signalling pathways which controls the osteogenic differentiation of stem cells, and Mg2+ can selectively activate the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway.56 The biphasic mode of Mg2+ in bone repair has been recently reported by Qiao et al.57 Mg-induced osteogenesis has been observed, suggesting the therapeutic potential of Mg2+ in orthopaedics.58-60 In addition, Mg2+ ions affect the seeded calcium phosphate crystallisation rate and subsequent hydroxyapatite growth.61 The total body stores of Mg are between 21 g and 28 g in the average 70 kg adult. Normal serum usually has a Mg range of 1.7 mg/dL to 2.5 mg/dL. Most of the body’s Mg is in the skeletal bone mass, which accounts for more than 50% of the body’s stores. The remainder is located in soft tissues, of which only 0.3% is located extracellularly. Of the total Mg consumed, approximately 30% to 50% is absorbed.62 Too much Mg from food does not pose a health risk because the kidneys eliminate excess amounts via the urine.63 However, a very high dose of Mg via, for example, dietary supplements or medications can result in diarrhoea that can be accompanied by nausea and abdominal cramping.64 The daily intake allowances of Mg are summarised in Table 3.65 ...
Crystal growth of calcium phosphates in the presence of magnesium ions
1
1985
... Mg is a nutrient that the body needs to stay healthy and is important for many processes. Mg is primarily found within the cells and is a cofactor in more than 300 enzymatic reactions, which are essential for the human body.52 The presence of Mg is vital for transmission and storage of energy to be used by cells.53 It also has a central role in cell growth and the structure and permeability of their membranes.52, 54 It has been reported that Mg2+ ions are able to aid the growth of bone marrow cells through the enhancement of bone morphogenetic protein receptor recognition and Smad signalling pathways.55 The mitogen-activated protein kinase/extracellular signal-regulated kinase pathway is one of the signalling pathways which controls the osteogenic differentiation of stem cells, and Mg2+ can selectively activate the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway.56 The biphasic mode of Mg2+ in bone repair has been recently reported by Qiao et al.57 Mg-induced osteogenesis has been observed, suggesting the therapeutic potential of Mg2+ in orthopaedics.58-60 In addition, Mg2+ ions affect the seeded calcium phosphate crystallisation rate and subsequent hydroxyapatite growth.61 The total body stores of Mg are between 21 g and 28 g in the average 70 kg adult. Normal serum usually has a Mg range of 1.7 mg/dL to 2.5 mg/dL. Most of the body’s Mg is in the skeletal bone mass, which accounts for more than 50% of the body’s stores. The remainder is located in soft tissues, of which only 0.3% is located extracellularly. Of the total Mg consumed, approximately 30% to 50% is absorbed.62 Too much Mg from food does not pose a health risk because the kidneys eliminate excess amounts via the urine.63 However, a very high dose of Mg via, for example, dietary supplements or medications can result in diarrhoea that can be accompanied by nausea and abdominal cramping.64 The daily intake allowances of Mg are summarised in Table 3.65 ...
Magnesium: its proven and potential clinical significance
1
2001
... Mg is a nutrient that the body needs to stay healthy and is important for many processes. Mg is primarily found within the cells and is a cofactor in more than 300 enzymatic reactions, which are essential for the human body.52 The presence of Mg is vital for transmission and storage of energy to be used by cells.53 It also has a central role in cell growth and the structure and permeability of their membranes.52, 54 It has been reported that Mg2+ ions are able to aid the growth of bone marrow cells through the enhancement of bone morphogenetic protein receptor recognition and Smad signalling pathways.55 The mitogen-activated protein kinase/extracellular signal-regulated kinase pathway is one of the signalling pathways which controls the osteogenic differentiation of stem cells, and Mg2+ can selectively activate the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway.56 The biphasic mode of Mg2+ in bone repair has been recently reported by Qiao et al.57 Mg-induced osteogenesis has been observed, suggesting the therapeutic potential of Mg2+ in orthopaedics.58-60 In addition, Mg2+ ions affect the seeded calcium phosphate crystallisation rate and subsequent hydroxyapatite growth.61 The total body stores of Mg are between 21 g and 28 g in the average 70 kg adult. Normal serum usually has a Mg range of 1.7 mg/dL to 2.5 mg/dL. Most of the body’s Mg is in the skeletal bone mass, which accounts for more than 50% of the body’s stores. The remainder is located in soft tissues, of which only 0.3% is located extracellularly. Of the total Mg consumed, approximately 30% to 50% is absorbed.62 Too much Mg from food does not pose a health risk because the kidneys eliminate excess amounts via the urine.63 However, a very high dose of Mg via, for example, dietary supplements or medications can result in diarrhoea that can be accompanied by nausea and abdominal cramping.64 The daily intake allowances of Mg are summarised in Table 3.65 ...
Magnesium metabolism in health and disease
1
2009
... Mg is a nutrient that the body needs to stay healthy and is important for many processes. Mg is primarily found within the cells and is a cofactor in more than 300 enzymatic reactions, which are essential for the human body.52 The presence of Mg is vital for transmission and storage of energy to be used by cells.53 It also has a central role in cell growth and the structure and permeability of their membranes.52, 54 It has been reported that Mg2+ ions are able to aid the growth of bone marrow cells through the enhancement of bone morphogenetic protein receptor recognition and Smad signalling pathways.55 The mitogen-activated protein kinase/extracellular signal-regulated kinase pathway is one of the signalling pathways which controls the osteogenic differentiation of stem cells, and Mg2+ can selectively activate the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway.56 The biphasic mode of Mg2+ in bone repair has been recently reported by Qiao et al.57 Mg-induced osteogenesis has been observed, suggesting the therapeutic potential of Mg2+ in orthopaedics.58-60 In addition, Mg2+ ions affect the seeded calcium phosphate crystallisation rate and subsequent hydroxyapatite growth.61 The total body stores of Mg are between 21 g and 28 g in the average 70 kg adult. Normal serum usually has a Mg range of 1.7 mg/dL to 2.5 mg/dL. Most of the body’s Mg is in the skeletal bone mass, which accounts for more than 50% of the body’s stores. The remainder is located in soft tissues, of which only 0.3% is located extracellularly. Of the total Mg consumed, approximately 30% to 50% is absorbed.62 Too much Mg from food does not pose a health risk because the kidneys eliminate excess amounts via the urine.63 However, a very high dose of Mg via, for example, dietary supplements or medications can result in diarrhoea that can be accompanied by nausea and abdominal cramping.64 The daily intake allowances of Mg are summarised in Table 3.65 ...
1
1997
... Mg is a nutrient that the body needs to stay healthy and is important for many processes. Mg is primarily found within the cells and is a cofactor in more than 300 enzymatic reactions, which are essential for the human body.52 The presence of Mg is vital for transmission and storage of energy to be used by cells.53 It also has a central role in cell growth and the structure and permeability of their membranes.52, 54 It has been reported that Mg2+ ions are able to aid the growth of bone marrow cells through the enhancement of bone morphogenetic protein receptor recognition and Smad signalling pathways.55 The mitogen-activated protein kinase/extracellular signal-regulated kinase pathway is one of the signalling pathways which controls the osteogenic differentiation of stem cells, and Mg2+ can selectively activate the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway.56 The biphasic mode of Mg2+ in bone repair has been recently reported by Qiao et al.57 Mg-induced osteogenesis has been observed, suggesting the therapeutic potential of Mg2+ in orthopaedics.58-60 In addition, Mg2+ ions affect the seeded calcium phosphate crystallisation rate and subsequent hydroxyapatite growth.61 The total body stores of Mg are between 21 g and 28 g in the average 70 kg adult. Normal serum usually has a Mg range of 1.7 mg/dL to 2.5 mg/dL. Most of the body’s Mg is in the skeletal bone mass, which accounts for more than 50% of the body’s stores. The remainder is located in soft tissues, of which only 0.3% is located extracellularly. Of the total Mg consumed, approximately 30% to 50% is absorbed.62 Too much Mg from food does not pose a health risk because the kidneys eliminate excess amounts via the urine.63 However, a very high dose of Mg via, for example, dietary supplements or medications can result in diarrhoea that can be accompanied by nausea and abdominal cramping.64 The daily intake allowances of Mg are summarised in Table 3.65 ...
Magnesium: fact sheet for health professionals
2
2021
... Mg is a nutrient that the body needs to stay healthy and is important for many processes. Mg is primarily found within the cells and is a cofactor in more than 300 enzymatic reactions, which are essential for the human body.52 The presence of Mg is vital for transmission and storage of energy to be used by cells.53 It also has a central role in cell growth and the structure and permeability of their membranes.52, 54 It has been reported that Mg2+ ions are able to aid the growth of bone marrow cells through the enhancement of bone morphogenetic protein receptor recognition and Smad signalling pathways.55 The mitogen-activated protein kinase/extracellular signal-regulated kinase pathway is one of the signalling pathways which controls the osteogenic differentiation of stem cells, and Mg2+ can selectively activate the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway.56 The biphasic mode of Mg2+ in bone repair has been recently reported by Qiao et al.57 Mg-induced osteogenesis has been observed, suggesting the therapeutic potential of Mg2+ in orthopaedics.58-60 In addition, Mg2+ ions affect the seeded calcium phosphate crystallisation rate and subsequent hydroxyapatite growth.61 The total body stores of Mg are between 21 g and 28 g in the average 70 kg adult. Normal serum usually has a Mg range of 1.7 mg/dL to 2.5 mg/dL. Most of the body’s Mg is in the skeletal bone mass, which accounts for more than 50% of the body’s stores. The remainder is located in soft tissues, of which only 0.3% is located extracellularly. Of the total Mg consumed, approximately 30% to 50% is absorbed.62 Too much Mg from food does not pose a health risk because the kidneys eliminate excess amounts via the urine.63 However, a very high dose of Mg via, for example, dietary supplements or medications can result in diarrhoea that can be accompanied by nausea and abdominal cramping.64 The daily intake allowances of Mg are summarised in Table 3.65 ...
... Note: Data are from Office of Dietary Supplements, National Institutes of Health.65 ...
Biodegradable magnesium-based screw clinically equivalent to titanium screw in hallux valgus surgery: short term results of the first prospective, randomized, controlled clinical pilot study
1
2013
... In the past, a number of investigations have been carried out on potential Mg-based implants for use in orthopaedic applications. Windhagen et al.66 reported that compression screws made of MgYREZr alloy showed good biocompatibility and osteoconductive properties. Cortical bone screws machined from AZ31 (Mg-3Al-1Zn) alloy have been implanted into hip bone,67 while intramedullary nails made of LAE442 (Mg-4Li-4Al-2RE) have been implanted into the marrow cavity of tibiae.68 However, very few monolithic Mg-based components are used in load-bearing applications (such as compression plates, bridging plates etc.) because of their too-rapid biodegradation rate. Thus biodegradable Mg implants need to be further explored. Moreover, Mg-based bioceramics, bioglasses, biocomposites and 3D-printed scaffolds need to be carefully designed. ...
Corrosion of magnesium alloy AZ31 screws is dependent on the implantation site
1
2011
... In the past, a number of investigations have been carried out on potential Mg-based implants for use in orthopaedic applications. Windhagen et al.66 reported that compression screws made of MgYREZr alloy showed good biocompatibility and osteoconductive properties. Cortical bone screws machined from AZ31 (Mg-3Al-1Zn) alloy have been implanted into hip bone,67 while intramedullary nails made of LAE442 (Mg-4Li-4Al-2RE) have been implanted into the marrow cavity of tibiae.68 However, very few monolithic Mg-based components are used in load-bearing applications (such as compression plates, bridging plates etc.) because of their too-rapid biodegradation rate. Thus biodegradable Mg implants need to be further explored. Moreover, Mg-based bioceramics, bioglasses, biocomposites and 3D-printed scaffolds need to be carefully designed. ...
Comparison of the resorbable magnesium. alloys LAE442 und MgCa0.8 concerning their mechanical properties, their progress of degradation and the bone-implant-contact after 12 months implantation duration in a rabbit model
1
2009
... In the past, a number of investigations have been carried out on potential Mg-based implants for use in orthopaedic applications. Windhagen et al.66 reported that compression screws made of MgYREZr alloy showed good biocompatibility and osteoconductive properties. Cortical bone screws machined from AZ31 (Mg-3Al-1Zn) alloy have been implanted into hip bone,67 while intramedullary nails made of LAE442 (Mg-4Li-4Al-2RE) have been implanted into the marrow cavity of tibiae.68 However, very few monolithic Mg-based components are used in load-bearing applications (such as compression plates, bridging plates etc.) because of their too-rapid biodegradation rate. Thus biodegradable Mg implants need to be further explored. Moreover, Mg-based bioceramics, bioglasses, biocomposites and 3D-printed scaffolds need to be carefully designed. ...
2
2004
... Suitable alloying elements need to be tailored to design and improve the mechanical and bio-corrosion properties of biomedical Mg alloys. Table 4 shows a brief summary of the various alloying elements used in Mg biomaterials.3, 38, 69-85 Alloying elements can strengthen the Mg alloys by solid solution strengthening, precipitation hardening and grain refinement strengthening. These alloying elements must have high and temperature-dependent solubility in Mg. High solubility of an alloying element can lead to significant precipitation hardening of Mg alloys, such as Mg-Al alloys, Mg-Zn alloys and Mg-rare earth (RE) alloys. Both solid solution strengthening and precipitation strengthening improve the strength, but generally cause deterioration in the ductility of Mg alloys. However, grain refinement strengthening improves both strength and ductility. It is widely acknowledged that the refinement efficiency of the alloying elements can be determined by their growth restriction factor.86-88 The growth restriction factor is a measure of the segregation power of an element during solidification. It is calculated from binary phase diagrams and equals ΣimiC0,i (ki﹣1), where mi is the slope of the liquidus line (assumed to be straight), ki is the distribution coefficient and C0,i is the initial concentration of element i.89 If an element has a large growth restriction factor (such as Zr, Ca, Zn) this means that the growth-restricting effect on the solid-liquid interface of the new grains is strong, thus preventing new grains from growing into the melt.90 These elements segregate strongly in the melt and cause intense constitutional supercooling in a diffusion layer ahead of the advancing solid/liquid interface, consequently promoting nucleation and restricting grain growth. Therefore, these elements can significantly refine the grains, which benefits both strength and ductility. ...
... Note: Superscript a indicates that the total amount of rare earth elements (Ce, La, Nd, Pr, Y) should not exceed 4.2 mg/day. Data are from Zheng et al.3, 38, 69-85 ...
Trace elements in human nutrition and health
1996
Aluminium, metals and dementia
2021
The coordination chemistry of aluminium in neurodegenerative disease
2012
What is the risk of aluminium as a neurotoxin?
2014
Influence of yttrium element on the corrosion behaviors of Mg-Y binary magnesium alloy
2017
Assessing the corrosion resistance of nonequilibrium magnesium-yttrium alloys
1
1995
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
Reported antiatherosclerotic activity of silicon may reflect increased endothelial synthesis of heparan sulfate proteoglycans
1997
The biological role of strontium
2004
ASM specialty handbook: magnesium and magnesium alloys
1999
Phase diagram of binary magnesium alloys
1988
4.3: Electrochemical potentials
2021
Elements, atomic radii and the periodic table: How big is an atom? Why does its size vary? How can we show this in CrystalMaker?
2021
Degradable biomaterials based on magnesium corrosion
2008
Performance-driven design of Biocompatible Mg alloys
1
2011
... Mg-Y and Mg-Nd-based alloys normally have an excellent combination of strength and elongation, and good corrosion resistance. Regarding biosafety, the amount of Y and Nd should be controlled to be below a threshold level. It is generally accepted that the total amount of Nd and Y should not exceed 4.2 mg/day.83, 84 Assuming that a Mg alloy implant degrades within 3 months, the total released amount of Nd and Y needs to be below 380 mg. For example, if the total weight of an implant is 6.9 g (calculated from the locking compression plate (LCP3.5-423.621)), then the total wt% of Nd and Y would need to be controlled to lie below 5wt%. ...
Recent advances on the development of magnesium alloys for biodegradable implants
3
2014
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
...
84 Copyright 2014, with permission from Acta Materialia Inc.
The in vitro and in vivo corrosion rates of Mg-based alloys are shown in Table 5.36, 38, 39, 94, 99, 100, 103, 108-117 The in vivo corrosion rates of Mg-1.2Mn-1Zn,36 Mg-0.8Ca115 and WE43115 alloys have been reported and compared.118 These alloys have a low in vivo corrosion rate. Corrosion resistance can be modified by thermal-mechanical processing: for example, as shown in as-cast and as-extruded AZ31 alloy, as-cast and as-rolled Mg-1Zn, as-cast and as-rolled Mg-1Zr. The Mg-RE-based alloys generally show good corrosion resistance, especially after thermal-mechanical processing, for example Mg-Nd-Zn-Zr, WE43 and Mg-Gd-Zn-Zr alloys (shown in Table 5). Note that Witte et al. have reported that the in vivo (animal model) degradation of AZ91D and LAE442 alloys was very different from the in vitro corrosion.109 The major reason for the differing corrosion behaviours is the dynamic nature of the in vivo environment and the static nature of the in vitro environment. In addition, the covering of proteins on implants, the remodelling of bones and possibly a protective corrosion layer in the in vivo environment may lead to a reduced corrosion rate.109 ...
... Mg-Y and Mg-Nd-based alloys normally have an excellent combination of strength and elongation, and good corrosion resistance. Regarding biosafety, the amount of Y and Nd should be controlled to be below a threshold level. It is generally accepted that the total amount of Nd and Y should not exceed 4.2 mg/day.83, 84 Assuming that a Mg alloy implant degrades within 3 months, the total released amount of Nd and Y needs to be below 380 mg. For example, if the total weight of an implant is 6.9 g (calculated from the locking compression plate (LCP3.5-423.621)), then the total wt% of Nd and Y would need to be controlled to lie below 5wt%. ...
Recommended daily intake of vitamins and minerals
2
2021
... Suitable alloying elements need to be tailored to design and improve the mechanical and bio-corrosion properties of biomedical Mg alloys. Table 4 shows a brief summary of the various alloying elements used in Mg biomaterials.3, 38, 69-85 Alloying elements can strengthen the Mg alloys by solid solution strengthening, precipitation hardening and grain refinement strengthening. These alloying elements must have high and temperature-dependent solubility in Mg. High solubility of an alloying element can lead to significant precipitation hardening of Mg alloys, such as Mg-Al alloys, Mg-Zn alloys and Mg-rare earth (RE) alloys. Both solid solution strengthening and precipitation strengthening improve the strength, but generally cause deterioration in the ductility of Mg alloys. However, grain refinement strengthening improves both strength and ductility. It is widely acknowledged that the refinement efficiency of the alloying elements can be determined by their growth restriction factor.86-88 The growth restriction factor is a measure of the segregation power of an element during solidification. It is calculated from binary phase diagrams and equals ΣimiC0,i (ki﹣1), where mi is the slope of the liquidus line (assumed to be straight), ki is the distribution coefficient and C0,i is the initial concentration of element i.89 If an element has a large growth restriction factor (such as Zr, Ca, Zn) this means that the growth-restricting effect on the solid-liquid interface of the new grains is strong, thus preventing new grains from growing into the melt.90 These elements segregate strongly in the melt and cause intense constitutional supercooling in a diffusion layer ahead of the advancing solid/liquid interface, consequently promoting nucleation and restricting grain growth. Therefore, these elements can significantly refine the grains, which benefits both strength and ductility. ...
... Note: Superscript a indicates that the total amount of rare earth elements (Ce, La, Nd, Pr, Y) should not exceed 4.2 mg/day. Data are from Zheng et al.3, 38, 69-85 ...
A model of grain refinement incorporating alloy constitution and potency of heterogeneous nucleant particles
1
2001
... Suitable alloying elements need to be tailored to design and improve the mechanical and bio-corrosion properties of biomedical Mg alloys. Table 4 shows a brief summary of the various alloying elements used in Mg biomaterials.3, 38, 69-85 Alloying elements can strengthen the Mg alloys by solid solution strengthening, precipitation hardening and grain refinement strengthening. These alloying elements must have high and temperature-dependent solubility in Mg. High solubility of an alloying element can lead to significant precipitation hardening of Mg alloys, such as Mg-Al alloys, Mg-Zn alloys and Mg-rare earth (RE) alloys. Both solid solution strengthening and precipitation strengthening improve the strength, but generally cause deterioration in the ductility of Mg alloys. However, grain refinement strengthening improves both strength and ductility. It is widely acknowledged that the refinement efficiency of the alloying elements can be determined by their growth restriction factor.86-88 The growth restriction factor is a measure of the segregation power of an element during solidification. It is calculated from binary phase diagrams and equals ΣimiC0,i (ki﹣1), where mi is the slope of the liquidus line (assumed to be straight), ki is the distribution coefficient and C0,i is the initial concentration of element i.89 If an element has a large growth restriction factor (such as Zr, Ca, Zn) this means that the growth-restricting effect on the solid-liquid interface of the new grains is strong, thus preventing new grains from growing into the melt.90 These elements segregate strongly in the melt and cause intense constitutional supercooling in a diffusion layer ahead of the advancing solid/liquid interface, consequently promoting nucleation and restricting grain growth. Therefore, these elements can significantly refine the grains, which benefits both strength and ductility. ...
Grain refinement of aluminum alloys: Part I. the nucleant and solute paradigms—a review of the literature
1999
Grain refinement of aluminum alloys: Part II. Confirmation of, and a mechanism for, the solute paradigm
1
1999
... Suitable alloying elements need to be tailored to design and improve the mechanical and bio-corrosion properties of biomedical Mg alloys. Table 4 shows a brief summary of the various alloying elements used in Mg biomaterials.3, 38, 69-85 Alloying elements can strengthen the Mg alloys by solid solution strengthening, precipitation hardening and grain refinement strengthening. These alloying elements must have high and temperature-dependent solubility in Mg. High solubility of an alloying element can lead to significant precipitation hardening of Mg alloys, such as Mg-Al alloys, Mg-Zn alloys and Mg-rare earth (RE) alloys. Both solid solution strengthening and precipitation strengthening improve the strength, but generally cause deterioration in the ductility of Mg alloys. However, grain refinement strengthening improves both strength and ductility. It is widely acknowledged that the refinement efficiency of the alloying elements can be determined by their growth restriction factor.86-88 The growth restriction factor is a measure of the segregation power of an element during solidification. It is calculated from binary phase diagrams and equals ΣimiC0,i (ki﹣1), where mi is the slope of the liquidus line (assumed to be straight), ki is the distribution coefficient and C0,i is the initial concentration of element i.89 If an element has a large growth restriction factor (such as Zr, Ca, Zn) this means that the growth-restricting effect on the solid-liquid interface of the new grains is strong, thus preventing new grains from growing into the melt.90 These elements segregate strongly in the melt and cause intense constitutional supercooling in a diffusion layer ahead of the advancing solid/liquid interface, consequently promoting nucleation and restricting grain growth. Therefore, these elements can significantly refine the grains, which benefits both strength and ductility. ...
Grain refinement of magnesium alloys
1
2005
... Suitable alloying elements need to be tailored to design and improve the mechanical and bio-corrosion properties of biomedical Mg alloys. Table 4 shows a brief summary of the various alloying elements used in Mg biomaterials.3, 38, 69-85 Alloying elements can strengthen the Mg alloys by solid solution strengthening, precipitation hardening and grain refinement strengthening. These alloying elements must have high and temperature-dependent solubility in Mg. High solubility of an alloying element can lead to significant precipitation hardening of Mg alloys, such as Mg-Al alloys, Mg-Zn alloys and Mg-rare earth (RE) alloys. Both solid solution strengthening and precipitation strengthening improve the strength, but generally cause deterioration in the ductility of Mg alloys. However, grain refinement strengthening improves both strength and ductility. It is widely acknowledged that the refinement efficiency of the alloying elements can be determined by their growth restriction factor.86-88 The growth restriction factor is a measure of the segregation power of an element during solidification. It is calculated from binary phase diagrams and equals ΣimiC0,i (ki﹣1), where mi is the slope of the liquidus line (assumed to be straight), ki is the distribution coefficient and C0,i is the initial concentration of element i.89 If an element has a large growth restriction factor (such as Zr, Ca, Zn) this means that the growth-restricting effect on the solid-liquid interface of the new grains is strong, thus preventing new grains from growing into the melt.90 These elements segregate strongly in the melt and cause intense constitutional supercooling in a diffusion layer ahead of the advancing solid/liquid interface, consequently promoting nucleation and restricting grain growth. Therefore, these elements can significantly refine the grains, which benefits both strength and ductility. ...
The role of solute in grain refinement of magnesium
1
2000
... Suitable alloying elements need to be tailored to design and improve the mechanical and bio-corrosion properties of biomedical Mg alloys. Table 4 shows a brief summary of the various alloying elements used in Mg biomaterials.3, 38, 69-85 Alloying elements can strengthen the Mg alloys by solid solution strengthening, precipitation hardening and grain refinement strengthening. These alloying elements must have high and temperature-dependent solubility in Mg. High solubility of an alloying element can lead to significant precipitation hardening of Mg alloys, such as Mg-Al alloys, Mg-Zn alloys and Mg-rare earth (RE) alloys. Both solid solution strengthening and precipitation strengthening improve the strength, but generally cause deterioration in the ductility of Mg alloys. However, grain refinement strengthening improves both strength and ductility. It is widely acknowledged that the refinement efficiency of the alloying elements can be determined by their growth restriction factor.86-88 The growth restriction factor is a measure of the segregation power of an element during solidification. It is calculated from binary phase diagrams and equals ΣimiC0,i (ki﹣1), where mi is the slope of the liquidus line (assumed to be straight), ki is the distribution coefficient and C0,i is the initial concentration of element i.89 If an element has a large growth restriction factor (such as Zr, Ca, Zn) this means that the growth-restricting effect on the solid-liquid interface of the new grains is strong, thus preventing new grains from growing into the melt.90 These elements segregate strongly in the melt and cause intense constitutional supercooling in a diffusion layer ahead of the advancing solid/liquid interface, consequently promoting nucleation and restricting grain growth. Therefore, these elements can significantly refine the grains, which benefits both strength and ductility. ...
Corrosion mechanisms of magnesium alloys
4
1999
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
... The corrosion behaviour of Mg alloys is closely related to their grain size. Grain refinement is an effective way to improve the corrosion performance of Mg alloys.48, 119-122 For example, Lu et al.111 found that the bio-corrosion rate of Mg-3Zn-0.3Ca is a function of grain size and the volume fraction of secondary phase. Birbilis et al.122 proposed that the corrosion rate increases as the logarithm of average grain size increases in pure Mg. Ralston et al.123 also described a relationship between corrosion rate and grain size: icorr=(A)+(B)·GS﹣0.5 (where A is a constant and a function of the environment; B is a material constant and is determined by the composition and impurity level of the material; GS is grain size and icorr is the corrosion rate). Corrosion resistance can be linearly enhanced by reducing the grain size. It has been reported that the reason why grain refinement causes a decreased corrosion rate is because of the improved passive film. A high grain boundary density promotes a better oxide film conduction rate on surfaces with low to passive corrosion rates and therefore a fine grain structure is more corrosion resistant.124, 125 Song and StJohn 126 indicated that the skin of the die-cast AZ91D alloy exhibits better corrosion performance than the interior, because of the more continuous Mg17Al12 phase formed around finer α-Mg grains. If the grains are small and the volume fraction of the Mg17Al12 phase is not too low, then the Mg17Al12 phase forms continuously like a net, and is difficult to undercut because corrosion development cannot easily progress through numerous Mg17Al12 precipitates. The Mg17Al12 phase is exposed and the α-Mg phase corrodes preferentially. Eventually, the final surface of the sample has large amounts of Mg17Al12 which are more corrosion resistant than the α-Mg phase, thus the corrosion resistance is enhanced.91, 127 ...
... Second phases have a significant impact on the performance of Mg alloys.128, 129 A homogenous microstructure is desirable, because a difference in corrosion potential between the α-Mg and the second phase causes micro-galvanic corrosion. In AZ alloys, the Mg17Al12 phase (﹣1.20 V) is nobler than the α-Mg matrix (﹣1.65 V)46 and therefore acts as a cathode and aggravates the corrosion of Mg.91, 130 Some researchers have proposed that the Mg17Al12 phase can act as a corrosion barrier and have a positive effect on corrosion resistance.128, 129, 131 The fraction and distribution of Mg17Al12 phases are important factors in determining which effect dominates. A finely- and continuously-distributed β-phase serves as a corrosion barrier and inhibits corrosion;119 otherwise, the β-phase promotes corrosion. Song et al.126 proposed that more continuous second phases can benefit the corrosion resistance of the Mg-RE-Zr alloy (MEZ alloy). The morphology of the second phase also affects the corrosion behaviour of Mg alloys. Srinivasan et al.132 reported that Mg with a coarse Chinese script Mg2Si phase shows a weaker corrosion performance than that with evenly-distributed polygonal-shaped Mg2Si phases. The reduction and refinement of Mg2Si phases also lead to better corrosion behaviour of Mg-Si(-Ca) alloys.91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
... 91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
First-principles studies on alloying and simplified thermodynamic aqueous chemical stability of calcium-, zinc-, aluminum-, yttrium- and iron-doped magnesium alloys
1
2010
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
The role of rare earth elements in biodegradable metals: A review
1
2021
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
Biocorrosion properties of as-extruded Mg-Nd-Zn-Zr alloy compared with commercial AZ31 and WE43 alloys
7
2012
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
... 94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
... The in vitro and in vivo corrosion rates of Mg-based alloys are shown in Table 5.36, 38, 39, 94, 99, 100, 103, 108-117 The in vivo corrosion rates of Mg-1.2Mn-1Zn,36 Mg-0.8Ca115 and WE43115 alloys have been reported and compared.118 These alloys have a low in vivo corrosion rate. Corrosion resistance can be modified by thermal-mechanical processing: for example, as shown in as-cast and as-extruded AZ31 alloy, as-cast and as-rolled Mg-1Zn, as-cast and as-rolled Mg-1Zr. The Mg-RE-based alloys generally show good corrosion resistance, especially after thermal-mechanical processing, for example Mg-Nd-Zn-Zr, WE43 and Mg-Gd-Zn-Zr alloys (shown in Table 5). Note that Witte et al. have reported that the in vivo (animal model) degradation of AZ91D and LAE442 alloys was very different from the in vitro corrosion.109 The major reason for the differing corrosion behaviours is the dynamic nature of the in vivo environment and the static nature of the in vitro environment. In addition, the covering of proteins on implants, the remodelling of bones and possibly a protective corrosion layer in the in vivo environment may lead to a reduced corrosion rate.109 ...
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
... ,
94 Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
...
94 Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
... Second phases have a significant impact on the performance of Mg alloys.128, 129 A homogenous microstructure is desirable, because a difference in corrosion potential between the α-Mg and the second phase causes micro-galvanic corrosion. In AZ alloys, the Mg17Al12 phase (﹣1.20 V) is nobler than the α-Mg matrix (﹣1.65 V)46 and therefore acts as a cathode and aggravates the corrosion of Mg.91, 130 Some researchers have proposed that the Mg17Al12 phase can act as a corrosion barrier and have a positive effect on corrosion resistance.128, 129, 131 The fraction and distribution of Mg17Al12 phases are important factors in determining which effect dominates. A finely- and continuously-distributed β-phase serves as a corrosion barrier and inhibits corrosion;119 otherwise, the β-phase promotes corrosion. Song et al.126 proposed that more continuous second phases can benefit the corrosion resistance of the Mg-RE-Zr alloy (MEZ alloy). The morphology of the second phase also affects the corrosion behaviour of Mg alloys. Srinivasan et al.132 reported that Mg with a coarse Chinese script Mg2Si phase shows a weaker corrosion performance than that with evenly-distributed polygonal-shaped Mg2Si phases. The reduction and refinement of Mg2Si phases also lead to better corrosion behaviour of Mg-Si(-Ca) alloys.91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
Microstructure, mechanical and bio-corrosion properties of Mg-Zn-Zr alloys with minor Ca addition
1
2017
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
Effect of Zn on mechanical property and corrosion property of extruded Mg-Zn-Mn alloy
1
2008
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
Microstructures and mechanical properties of the age hardened Mg-4.2Y-2.5Nd-1Gd-0.6Zr (WE43) microalloyed with Zn
1
2014
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
On the in vitro and in vivo degradation performance and biological response of new biodegradable Mg-Y-Zn alloys
1
2010
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
Preparation and properties of high purity Mg-Y biomaterials
3
2010
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
... The in vitro and in vivo corrosion rates of Mg-based alloys are shown in Table 5.36, 38, 39, 94, 99, 100, 103, 108-117 The in vivo corrosion rates of Mg-1.2Mn-1Zn,36 Mg-0.8Ca115 and WE43115 alloys have been reported and compared.118 These alloys have a low in vivo corrosion rate. Corrosion resistance can be modified by thermal-mechanical processing: for example, as shown in as-cast and as-extruded AZ31 alloy, as-cast and as-rolled Mg-1Zn, as-cast and as-rolled Mg-1Zr. The Mg-RE-based alloys generally show good corrosion resistance, especially after thermal-mechanical processing, for example Mg-Nd-Zn-Zr, WE43 and Mg-Gd-Zn-Zr alloys (shown in Table 5). Note that Witte et al. have reported that the in vivo (animal model) degradation of AZ91D and LAE442 alloys was very different from the in vitro corrosion.109 The major reason for the differing corrosion behaviours is the dynamic nature of the in vivo environment and the static nature of the in vitro environment. In addition, the covering of proteins on implants, the remodelling of bones and possibly a protective corrosion layer in the in vivo environment may lead to a reduced corrosion rate.109 ...
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
The role of β1’ precipitates in the bio-corrosion performance of Mg-3Zn in simulated body fluid
3
2014
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
... The in vitro and in vivo corrosion rates of Mg-based alloys are shown in Table 5.36, 38, 39, 94, 99, 100, 103, 108-117 The in vivo corrosion rates of Mg-1.2Mn-1Zn,36 Mg-0.8Ca115 and WE43115 alloys have been reported and compared.118 These alloys have a low in vivo corrosion rate. Corrosion resistance can be modified by thermal-mechanical processing: for example, as shown in as-cast and as-extruded AZ31 alloy, as-cast and as-rolled Mg-1Zn, as-cast and as-rolled Mg-1Zr. The Mg-RE-based alloys generally show good corrosion resistance, especially after thermal-mechanical processing, for example Mg-Nd-Zn-Zr, WE43 and Mg-Gd-Zn-Zr alloys (shown in Table 5). Note that Witte et al. have reported that the in vivo (animal model) degradation of AZ91D and LAE442 alloys was very different from the in vitro corrosion.109 The major reason for the differing corrosion behaviours is the dynamic nature of the in vivo environment and the static nature of the in vitro environment. In addition, the covering of proteins on implants, the remodelling of bones and possibly a protective corrosion layer in the in vivo environment may lead to a reduced corrosion rate.109 ...
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
Effects of minor Sr addition on microstructure, mechanical and bio-corrosion properties of the Mg-5Zn based alloy system
1
2017
... Second phases have a significant impact on the performance of Mg alloys.128, 129 A homogenous microstructure is desirable, because a difference in corrosion potential between the α-Mg and the second phase causes micro-galvanic corrosion. In AZ alloys, the Mg17Al12 phase (﹣1.20 V) is nobler than the α-Mg matrix (﹣1.65 V)46 and therefore acts as a cathode and aggravates the corrosion of Mg.91, 130 Some researchers have proposed that the Mg17Al12 phase can act as a corrosion barrier and have a positive effect on corrosion resistance.128, 129, 131 The fraction and distribution of Mg17Al12 phases are important factors in determining which effect dominates. A finely- and continuously-distributed β-phase serves as a corrosion barrier and inhibits corrosion;119 otherwise, the β-phase promotes corrosion. Song et al.126 proposed that more continuous second phases can benefit the corrosion resistance of the Mg-RE-Zr alloy (MEZ alloy). The morphology of the second phase also affects the corrosion behaviour of Mg alloys. Srinivasan et al.132 reported that Mg with a coarse Chinese script Mg2Si phase shows a weaker corrosion performance than that with evenly-distributed polygonal-shaped Mg2Si phases. The reduction and refinement of Mg2Si phases also lead to better corrosion behaviour of Mg-Si(-Ca) alloys.91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
Three-dimensional analysis of the microstructure and bio-corrosion of Mg-Zn and Mg-Zn-Ca alloys
1
2016
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
The development of binary Mg-Ca alloys for use as biodegradable materials within bone
3
2008
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
... The in vitro and in vivo corrosion rates of Mg-based alloys are shown in Table 5.36, 38, 39, 94, 99, 100, 103, 108-117 The in vivo corrosion rates of Mg-1.2Mn-1Zn,36 Mg-0.8Ca115 and WE43115 alloys have been reported and compared.118 These alloys have a low in vivo corrosion rate. Corrosion resistance can be modified by thermal-mechanical processing: for example, as shown in as-cast and as-extruded AZ31 alloy, as-cast and as-rolled Mg-1Zn, as-cast and as-rolled Mg-1Zr. The Mg-RE-based alloys generally show good corrosion resistance, especially after thermal-mechanical processing, for example Mg-Nd-Zn-Zr, WE43 and Mg-Gd-Zn-Zr alloys (shown in Table 5). Note that Witte et al. have reported that the in vivo (animal model) degradation of AZ91D and LAE442 alloys was very different from the in vitro corrosion.109 The major reason for the differing corrosion behaviours is the dynamic nature of the in vivo environment and the static nature of the in vitro environment. In addition, the covering of proteins on implants, the remodelling of bones and possibly a protective corrosion layer in the in vivo environment may lead to a reduced corrosion rate.109 ...
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
Preparation and characterization of a new biomedical Mg-Zn-Ca alloy
1
2012
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
Tomographic investigation of the effects of second phases on the biodegradation and nano-mechanical performance of a Mg-Zn-Ca alloy
4
2018
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
... 4) Micro-computed tomography (a non-destructive technique) has been demonstrated to be a powerful technique to monitor in vitro degradation.105, 188-190 The evaluation of the bio-corrosion rate depends on a comprehensive observation of the Mg specimen before and after immersion testing. The volume losses of the samples can be calculated and then converted to the same units (mm/year). Lu et al.105 reported the corrosion morphology and degradation rate of Mg-3Zn-0.3Ca alloys using three-dimensional reconstructions, as shown in Figure 7. The as-cast Mg-3Zn-0.3Ca has been severely attacked by corrosion and has lost 34.3% of its initial volume. ...
... 105 reported the corrosion morphology and degradation rate of Mg-3Zn-0.3Ca alloys using three-dimensional reconstructions, as shown in Figure 7. The as-cast Mg-3Zn-0.3Ca has been severely attacked by corrosion and has lost 34.3% of its initial volume. ...
...
105 Copyright 2018, with permission from Acta Materialia Inc.
In vivo testing ...
Microstructure, mechanical properties and bio-corrosion properties of Mg-Si(-Ca, Zn) alloy for biomedical application
3
2010
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
... 2) A hydrogen evolution method has been developed by Song et al.182 based on the collection of hydrogen gas during degradation of Mg in aqueous solutions. The hydrogen evolution measurement is currently very popular and is widely accepted by many researchers.10, 42, 59, 106, 107, 178-181 The mechanism of this measurement is simple and easy to understand, and is based on the reaction below: ...
... 3) Electrochemical measurement is widely used to measure the in vitro degradation behaviour of Mg alloys. The greatest advantage is that it can be used to obtain the real-time corrosion rate.106, 148, 183-185 Changes in corrosion behaviour can be instantaneously observed. Generally, the Mg sample is used as the working electrode, platinum as the counter electrode and a saturated calomel electrode as the reference electrode. Using this method, more corrosion information can be accessed, such as the relative rates of the anodic and cathodic reactions over a range of potentials.186 A number of investigations indicate that the corrosion rate of Mg alloys measured by electrochemical testing agrees with that by hydrogen evolution and helps to increase the understanding of how corrosion takes place.119, 186, 187 ...
Microstructure, mechanical properties, bio-corrosion properties and cytotoxicity of as-extruded Mg-Sr alloys
2
2017
... The second aspect to be considered is the effects of alloying elements on the bio-corrosion behaviour. The addition of some alloying elements can improve corrosion resistance by reacting with impurities. For example, Mn and Zn can overcome the harmful corrosion effects of impurities (such as Fe and Ni) by transforming impurities into harmless intermetallic compounds.91 Alloying Mg with Y can enhance the corrosion resistance, because of the formation of a stable and less chemically-reactive hydroxide protective film.75, 92 Moreover, alloying elements which form secondary phases with a similar corrosion potential (Ecorr) can reduce internal galvanic corrosion.The third consideration is the biocompatibility of alloying elements. The released metallic ions resulting from the degradation of Mg alloys need to be non-toxic or to be tolerated at low concentrations, below the threshold level. Elements can be categorised into different groups: 1) nutrient elements: Ca, Zn, Si, Sr; 2) allergic elements (elements likely to cause severe hepatotoxicity or other allergic problems): Al, Co, V, Cr, Ni, Ce, La, Cu, Pr; and 3) toxic elements: Cd, Be, Pb, Ba, Th. It has been reported that some RE elements (such as Y, Nd, Ho, Dy and Gd) have little influence on cell viability and haemolysis rates, but that other RE elements (such as La, Ce, etc.) need to be carefully controlled.93 Notably, the total amount of RE elements (Ce, La, Nd, Pr, Y) should be carefully controlled (below 4.2 mg/day).Commercially-available Mg alloys can be divided into four major groups: 1) Al-containing Mg alloys, such as AZ31 (Mg-3Al-1Zn),94 AZ61 (Mg-6Al-1Zn), AZ91 (Mg-9Al-1Zn) and AM60 (Mg-6Al-0.3Mn); 2) Al-free Mg alloys, such as ZK30 (Mg-3Zn-0.6Zr),95 ZK60 (Mg-3Zn-0.6Zr) and Mg-Mn-Zn;96 3) RE-containing alloys, such as WE43 (Mg-4Y-3RE-0.5Zr),94, 97 LAE442 (Mg-4Li-4Al-2RE), WZ21 (Mg-2Y-1Zn)98 and Mg-Y;38, 99 and 4) nutrient element-containing alloys, such as Mg-Zn,100-102 Mg-Ca,103 Mg-Zn-Ca,45, 104, 105 Mg-Si106 and Mg-Sr.107 The large range of mechanical properties of Mg alloys is shown in Figure 5.45, 84 An appropriate amount of Al, Ca and Zn can increase both the strength and ductility concurrently. Zr restricts grain growth and benefits the mechanical properties. Among these Mg-based alloys, Mg-RE-based alloys normally have a superior combined strength and elongation. Mg-Zn based-alloys are also very promising and exhibit good strength and elongation compared with other systems. ...
... 2) A hydrogen evolution method has been developed by Song et al.182 based on the collection of hydrogen gas during degradation of Mg in aqueous solutions. The hydrogen evolution measurement is currently very popular and is widely accepted by many researchers.10, 42, 59, 106, 107, 178-181 The mechanism of this measurement is simple and easy to understand, and is based on the reaction below: ...
Corrosion behaviors of Mg and its alloys with different Al contents in a modified simulated body fluid
2
2009
... The in vitro and in vivo corrosion rates of Mg-based alloys are shown in Table 5.36, 38, 39, 94, 99, 100, 103, 108-117 The in vivo corrosion rates of Mg-1.2Mn-1Zn,36 Mg-0.8Ca115 and WE43115 alloys have been reported and compared.118 These alloys have a low in vivo corrosion rate. Corrosion resistance can be modified by thermal-mechanical processing: for example, as shown in as-cast and as-extruded AZ31 alloy, as-cast and as-rolled Mg-1Zn, as-cast and as-rolled Mg-1Zr. The Mg-RE-based alloys generally show good corrosion resistance, especially after thermal-mechanical processing, for example Mg-Nd-Zn-Zr, WE43 and Mg-Gd-Zn-Zr alloys (shown in Table 5). Note that Witte et al. have reported that the in vivo (animal model) degradation of AZ91D and LAE442 alloys was very different from the in vitro corrosion.109 The major reason for the differing corrosion behaviours is the dynamic nature of the in vivo environment and the static nature of the in vitro environment. In addition, the covering of proteins on implants, the remodelling of bones and possibly a protective corrosion layer in the in vivo environment may lead to a reduced corrosion rate.109 ...
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
In vitro and in vivo corrosion measurements of magnesium alloys
5
2006
... The in vitro and in vivo corrosion rates of Mg-based alloys are shown in Table 5.36, 38, 39, 94, 99, 100, 103, 108-117 The in vivo corrosion rates of Mg-1.2Mn-1Zn,36 Mg-0.8Ca115 and WE43115 alloys have been reported and compared.118 These alloys have a low in vivo corrosion rate. Corrosion resistance can be modified by thermal-mechanical processing: for example, as shown in as-cast and as-extruded AZ31 alloy, as-cast and as-rolled Mg-1Zn, as-cast and as-rolled Mg-1Zr. The Mg-RE-based alloys generally show good corrosion resistance, especially after thermal-mechanical processing, for example Mg-Nd-Zn-Zr, WE43 and Mg-Gd-Zn-Zr alloys (shown in Table 5). Note that Witte et al. have reported that the in vivo (animal model) degradation of AZ91D and LAE442 alloys was very different from the in vitro corrosion.109 The major reason for the differing corrosion behaviours is the dynamic nature of the in vivo environment and the static nature of the in vitro environment. In addition, the covering of proteins on implants, the remodelling of bones and possibly a protective corrosion layer in the in vivo environment may lead to a reduced corrosion rate.109 ...
... 109 ...
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
... The in vivo assessment of the compatibility of biomaterials and medical devices with tissue is important for the development and implementation of implants for human use. Many in vivo studies have been conducted to understand the degradation process and the associated mechanisms. Animal models are adopted in order to determine the response to the biomaterials or medical devices, such as the interactions of various cell types with the implants, endocrine factors acting on cells around the implant and interactions with blood-borne cells and proteins. In vivo studies have mainly been performed on small animals, such as guinea pigs, rats and rabbits. Heublein et al.191 investigated a cardiovascular stent (AE21 alloy) in domestic pigs. There is a report describing the implantation of Mg chips into the spines of sheep.192 The first comprehensive in vivo study on Mg alloys was carried out by Witte et al.39 on four different Mg alloys (AZ31, AZ91, WE43 and LAE442), and these four Mg alloys were implanted into the femurs of guinea pigs. A newly-formed mineral phase was observed on the surface of the Mg implants during implant degradation, which stained with calcein green under fluorescent light (Figure 8A).39 The in vivo bio-corrosion morphology of the remaining Mg alloy in the guinea pig femora is shown in Figures 8B and C.109 It can be seen that the AZ91D rod was almost completely corroded, while the LAE442 rod was corroded more uniformly. Both of these Mg alloys exhibited good biocompatibility as evidenced by the direct contact with newly-formed bone. ...
... ,
109 Copyright 2005 & 2006, with permission from Elsevier Ltd.
Recently, some in vivo studies were carried out on large animal models. A goat was used to study the clinical capability of osteosynthesis of a lean Mg alloy (Mg-0.45Zn-0.45Ca) screw.51 In vivo transformation experiments on high-purity weight-bearing Mg screws were also carried out on goats.193 Small animals (rats) and large animals (sheep) have been used to compare the biodegradation rate, bone formation and in-growth of bone into Mg-0.45Zn-0.45Ca implants.194 A pig model was designed to evaluate the in vivo performance of a Mg-4Zn-0.1Sr anastomosis ring.195 A miniature pig has been employed to perform pre-clinical testing of human-sized Mg implants at multiple implantation sites.196 ...
Mechanical properties, degradation performance and cytotoxicity of Mg-Zn-Ca biomedical alloys with different compositions
2
2011
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
...
110 Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
Effects of secondary phase and grain size on the corrosion of biodegradable Mg-Zn-Ca alloys
2
2015
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
... The corrosion behaviour of Mg alloys is closely related to their grain size. Grain refinement is an effective way to improve the corrosion performance of Mg alloys.48, 119-122 For example, Lu et al.111 found that the bio-corrosion rate of Mg-3Zn-0.3Ca is a function of grain size and the volume fraction of secondary phase. Birbilis et al.122 proposed that the corrosion rate increases as the logarithm of average grain size increases in pure Mg. Ralston et al.123 also described a relationship between corrosion rate and grain size: icorr=(A)+(B)·GS﹣0.5 (where A is a constant and a function of the environment; B is a material constant and is determined by the composition and impurity level of the material; GS is grain size and icorr is the corrosion rate). Corrosion resistance can be linearly enhanced by reducing the grain size. It has been reported that the reason why grain refinement causes a decreased corrosion rate is because of the improved passive film. A high grain boundary density promotes a better oxide film conduction rate on surfaces with low to passive corrosion rates and therefore a fine grain structure is more corrosion resistant.124, 125 Song and StJohn 126 indicated that the skin of the die-cast AZ91D alloy exhibits better corrosion performance than the interior, because of the more continuous Mg17Al12 phase formed around finer α-Mg grains. If the grains are small and the volume fraction of the Mg17Al12 phase is not too low, then the Mg17Al12 phase forms continuously like a net, and is difficult to undercut because corrosion development cannot easily progress through numerous Mg17Al12 precipitates. The Mg17Al12 phase is exposed and the α-Mg phase corrodes preferentially. Eventually, the final surface of the sample has large amounts of Mg17Al12 which are more corrosion resistant than the α-Mg phase, thus the corrosion resistance is enhanced.91, 127 ...
Effect of Mn addition on corrosion properties of biodegradable Mg-4Zn-0.5Ca-xMn alloys
1
2017
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
Microstructure, mechanical properties and corrosion properties of Mg-Zn-Y alloys with low Zn content
1
2008
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
Biocorrosion behavior and cytotoxicity of a Mg-Gd-Zn-Zr alloy with long period stacking ordered structure
1
2012
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
Degradation behaviour and mechanical properties of magnesium implants in rabbit tibiae
3
2010
... The in vitro and in vivo corrosion rates of Mg-based alloys are shown in Table 5.36, 38, 39, 94, 99, 100, 103, 108-117 The in vivo corrosion rates of Mg-1.2Mn-1Zn,36 Mg-0.8Ca115 and WE43115 alloys have been reported and compared.118 These alloys have a low in vivo corrosion rate. Corrosion resistance can be modified by thermal-mechanical processing: for example, as shown in as-cast and as-extruded AZ31 alloy, as-cast and as-rolled Mg-1Zn, as-cast and as-rolled Mg-1Zr. The Mg-RE-based alloys generally show good corrosion resistance, especially after thermal-mechanical processing, for example Mg-Nd-Zn-Zr, WE43 and Mg-Gd-Zn-Zr alloys (shown in Table 5). Note that Witte et al. have reported that the in vivo (animal model) degradation of AZ91D and LAE442 alloys was very different from the in vitro corrosion.109 The major reason for the differing corrosion behaviours is the dynamic nature of the in vivo environment and the static nature of the in vitro environment. In addition, the covering of proteins on implants, the remodelling of bones and possibly a protective corrosion layer in the in vivo environment may lead to a reduced corrosion rate.109 ...
... 115 alloys have been reported and compared.118 These alloys have a low in vivo corrosion rate. Corrosion resistance can be modified by thermal-mechanical processing: for example, as shown in as-cast and as-extruded AZ31 alloy, as-cast and as-rolled Mg-1Zn, as-cast and as-rolled Mg-1Zr. The Mg-RE-based alloys generally show good corrosion resistance, especially after thermal-mechanical processing, for example Mg-Nd-Zn-Zr, WE43 and Mg-Gd-Zn-Zr alloys (shown in Table 5). Note that Witte et al. have reported that the in vivo (animal model) degradation of AZ91D and LAE442 alloys was very different from the in vitro corrosion.109 The major reason for the differing corrosion behaviours is the dynamic nature of the in vivo environment and the static nature of the in vitro environment. In addition, the covering of proteins on implants, the remodelling of bones and possibly a protective corrosion layer in the in vivo environment may lead to a reduced corrosion rate.109 ...
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
In vitro and in vivo studies on a Mg-Sr binary alloy system developed as a new kind of biodegradable metal
1
2012
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
Research on an Mg-Zn alloy as a degradable biomaterial
3
2010
... The in vitro and in vivo corrosion rates of Mg-based alloys are shown in Table 5.36, 38, 39, 94, 99, 100, 103, 108-117 The in vivo corrosion rates of Mg-1.2Mn-1Zn,36 Mg-0.8Ca115 and WE43115 alloys have been reported and compared.118 These alloys have a low in vivo corrosion rate. Corrosion resistance can be modified by thermal-mechanical processing: for example, as shown in as-cast and as-extruded AZ31 alloy, as-cast and as-rolled Mg-1Zn, as-cast and as-rolled Mg-1Zr. The Mg-RE-based alloys generally show good corrosion resistance, especially after thermal-mechanical processing, for example Mg-Nd-Zn-Zr, WE43 and Mg-Gd-Zn-Zr alloys (shown in Table 5). Note that Witte et al. have reported that the in vivo (animal model) degradation of AZ91D and LAE442 alloys was very different from the in vitro corrosion.109 The major reason for the differing corrosion behaviours is the dynamic nature of the in vivo environment and the static nature of the in vitro environment. In addition, the covering of proteins on implants, the remodelling of bones and possibly a protective corrosion layer in the in vivo environment may lead to a reduced corrosion rate.109 ...
... Bio-corrosion properties of magnesium-based alloys.
Alloy | Condition | In vitro corrosion rate (mm/year) | In vivo corrosion rate (mm/year) | Reference |
Mg-0.8Ca | As-extruded | - | 0.5 | 115 |
Mg-1Ca | As-cast | ﹣ | 1.27 | 103 |
Mg-1Al | As-cast | 2.07 | ﹣ | 38 |
Mg-1Zn | As-cast | 1.52 | ﹣ | 38 |
Mg-1Zn | As-rolled | 0.92 | ﹣ | 38 |
Mg-1Zr | As-cast | 2.2 | ﹣ | 38 |
Mg-1Zr | As-rolled | 0.91 | ﹣ | 38 |
Mg-1Sn | As-cast | 2.45 | ﹣ | 38 |
Mg-2Sr | As-rolled | 0.37 | 1.01 | 116 |
Mg-3Zn | Solution treated | 1.53 | ﹣ | 100 |
Mg-6Zn | As-extruded | 0.07 | 2.32 | 117 |
Mg-8Y | As-cast | 2.17 | ﹣ | 99 |
AZ31 | As-cast | 2 | 1.17 | 39 |
AZ31 | As-extruded | 0.21 | ﹣ | 94 |
AZ61 | As-cast | 0.73 | ﹣ | 108 |
AZ91D | As-cast | 2.8 | 1.38 | 109 |
WE43 | As-cast | 0.26 | 1.56 | 39, 94 |
Mg-1.2Mn-1Zn | As-cast | ﹣ | 0.45 | 36 |
Mg-1Zn-1Ca | As-cast | 2.13 | ﹣ | 110 |
Mg-3Zn-0.3Ca | Solution treated | 0.81 | ﹣ | 111 |
Mg-6Zn-1Ca | As-cast | 9.21 | ﹣ | 110 |
Mg-4Zn-0.5Ca-0.4Mn | As-cast | 0.25 | ﹣ | 112 |
Mg-3.09Nd-0.22Zn-0.44Zr | As-extruded | 0.13 | ﹣ | 94 |
Mg-2Zn-1.53Y | As-extruded | 0.7 | ﹣ | 113 |
Mg-11.3Gd-2.5Zn-0.7Zr | As-extruded | 0.17 | ﹣ | 114 |
In summary, amongst these Mg-based alloys, Mg-Zn-based alloys are very promising, not only exhibiting good strength and elongation compared with other systems, but also showing enhanced corrosion resistance. Moreover, Mg-Zn alloys have good biocompatibility, because Zn is an essential trace element in the human body. ...
... The tested Mg specimen is placed in the corrosion medium for a period of time, at the end of which the Mg alloy is taken out and washed with a cleaning solution (such as dilute chromic acid) to remove all corrosion products and then the resultant mass change is measured. This classic method has been used by a number of researchers.117, 176-181 ...
Novel magnesium alloys developed for biomedical application: a review
2
2013
... The in vitro and in vivo corrosion rates of Mg-based alloys are shown in Table 5.36, 38, 39, 94, 99, 100, 103, 108-117 The in vivo corrosion rates of Mg-1.2Mn-1Zn,36 Mg-0.8Ca115 and WE43115 alloys have been reported and compared.118 These alloys have a low in vivo corrosion rate. Corrosion resistance can be modified by thermal-mechanical processing: for example, as shown in as-cast and as-extruded AZ31 alloy, as-cast and as-rolled Mg-1Zn, as-cast and as-rolled Mg-1Zr. The Mg-RE-based alloys generally show good corrosion resistance, especially after thermal-mechanical processing, for example Mg-Nd-Zn-Zr, WE43 and Mg-Gd-Zn-Zr alloys (shown in Table 5). Note that Witte et al. have reported that the in vivo (animal model) degradation of AZ91D and LAE442 alloys was very different from the in vitro corrosion.109 The major reason for the differing corrosion behaviours is the dynamic nature of the in vivo environment and the static nature of the in vitro environment. In addition, the covering of proteins on implants, the remodelling of bones and possibly a protective corrosion layer in the in vivo environment may lead to a reduced corrosion rate.109 ...
... Besides the traditional techniques such as melting and casting, other fabrication methods have been developed to obtain biomedical Mg implants, including powder metallurgy, metallic glass forming and laser additive manufacturing. The different fabrication processes directly affect the microstructure and relevant biological performance, mechanical properties and bio-corrosion behaviour.118, 171 In particular, the accurate regulation of alloying elements, microstructure design, biocompatibility tailoring, machinability and precise control of porous structure need to be considered and further investigated. Moreover, the in vitro and in vivo testing needs to be carefully studied. ...
Influence of microstructure on the corrosion of diecast AZ91D
3
1998
... The corrosion behaviour of Mg alloys is closely related to their grain size. Grain refinement is an effective way to improve the corrosion performance of Mg alloys.48, 119-122 For example, Lu et al.111 found that the bio-corrosion rate of Mg-3Zn-0.3Ca is a function of grain size and the volume fraction of secondary phase. Birbilis et al.122 proposed that the corrosion rate increases as the logarithm of average grain size increases in pure Mg. Ralston et al.123 also described a relationship between corrosion rate and grain size: icorr=(A)+(B)·GS﹣0.5 (where A is a constant and a function of the environment; B is a material constant and is determined by the composition and impurity level of the material; GS is grain size and icorr is the corrosion rate). Corrosion resistance can be linearly enhanced by reducing the grain size. It has been reported that the reason why grain refinement causes a decreased corrosion rate is because of the improved passive film. A high grain boundary density promotes a better oxide film conduction rate on surfaces with low to passive corrosion rates and therefore a fine grain structure is more corrosion resistant.124, 125 Song and StJohn 126 indicated that the skin of the die-cast AZ91D alloy exhibits better corrosion performance than the interior, because of the more continuous Mg17Al12 phase formed around finer α-Mg grains. If the grains are small and the volume fraction of the Mg17Al12 phase is not too low, then the Mg17Al12 phase forms continuously like a net, and is difficult to undercut because corrosion development cannot easily progress through numerous Mg17Al12 precipitates. The Mg17Al12 phase is exposed and the α-Mg phase corrodes preferentially. Eventually, the final surface of the sample has large amounts of Mg17Al12 which are more corrosion resistant than the α-Mg phase, thus the corrosion resistance is enhanced.91, 127 ...
... Second phases have a significant impact on the performance of Mg alloys.128, 129 A homogenous microstructure is desirable, because a difference in corrosion potential between the α-Mg and the second phase causes micro-galvanic corrosion. In AZ alloys, the Mg17Al12 phase (﹣1.20 V) is nobler than the α-Mg matrix (﹣1.65 V)46 and therefore acts as a cathode and aggravates the corrosion of Mg.91, 130 Some researchers have proposed that the Mg17Al12 phase can act as a corrosion barrier and have a positive effect on corrosion resistance.128, 129, 131 The fraction and distribution of Mg17Al12 phases are important factors in determining which effect dominates. A finely- and continuously-distributed β-phase serves as a corrosion barrier and inhibits corrosion;119 otherwise, the β-phase promotes corrosion. Song et al.126 proposed that more continuous second phases can benefit the corrosion resistance of the Mg-RE-Zr alloy (MEZ alloy). The morphology of the second phase also affects the corrosion behaviour of Mg alloys. Srinivasan et al.132 reported that Mg with a coarse Chinese script Mg2Si phase shows a weaker corrosion performance than that with evenly-distributed polygonal-shaped Mg2Si phases. The reduction and refinement of Mg2Si phases also lead to better corrosion behaviour of Mg-Si(-Ca) alloys.91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
... 3) Electrochemical measurement is widely used to measure the in vitro degradation behaviour of Mg alloys. The greatest advantage is that it can be used to obtain the real-time corrosion rate.106, 148, 183-185 Changes in corrosion behaviour can be instantaneously observed. Generally, the Mg sample is used as the working electrode, platinum as the counter electrode and a saturated calomel electrode as the reference electrode. Using this method, more corrosion information can be accessed, such as the relative rates of the anodic and cathodic reactions over a range of potentials.186 A number of investigations indicate that the corrosion rate of Mg alloys measured by electrochemical testing agrees with that by hydrogen evolution and helps to increase the understanding of how corrosion takes place.119, 186, 187 ...
Effect of grain size and twins on corrosion behaviour of AZ31B magnesium alloy
1
2010
... Several researchers report that twins, texture and dislocations all have influences on the corrosion performance. Aung and Zhou120 reported that the existence of twins can accelerate the corrosion of Mg alloys. After equal channel angular extrusion, a higher density of dislocations and twins appeared and a more severe dissolution of the anode resulted.121 Andrei et al.136 reported that the equilibrium potential in the vicinity of the dislocations is locally reduced, thus causing accelerated dissolution of the anode. According to Xin et al.137 extruded AZ31 sheet showed better corrosion resistance because of the initial basal texture. Schmutz et al.138 reported that filaments of corrosion propagated at twin boundaries; this corrosion took place on a plane near the basal plane and then propagated down the prismatic planes. ...
The relation between severe plastic deformation microstructure and corrosion behavior of AZ31 magnesium alloy
1
2009
... Several researchers report that twins, texture and dislocations all have influences on the corrosion performance. Aung and Zhou120 reported that the existence of twins can accelerate the corrosion of Mg alloys. After equal channel angular extrusion, a higher density of dislocations and twins appeared and a more severe dissolution of the anode resulted.121 Andrei et al.136 reported that the equilibrium potential in the vicinity of the dislocations is locally reduced, thus causing accelerated dissolution of the anode. According to Xin et al.137 extruded AZ31 sheet showed better corrosion resistance because of the initial basal texture. Schmutz et al.138 reported that filaments of corrosion propagated at twin boundaries; this corrosion took place on a plane near the basal plane and then propagated down the prismatic planes. ...
Grain character influences on corrosion of ECAPed pure magnesium
2
2010
... The corrosion behaviour of Mg alloys is closely related to their grain size. Grain refinement is an effective way to improve the corrosion performance of Mg alloys.48, 119-122 For example, Lu et al.111 found that the bio-corrosion rate of Mg-3Zn-0.3Ca is a function of grain size and the volume fraction of secondary phase. Birbilis et al.122 proposed that the corrosion rate increases as the logarithm of average grain size increases in pure Mg. Ralston et al.123 also described a relationship between corrosion rate and grain size: icorr=(A)+(B)·GS﹣0.5 (where A is a constant and a function of the environment; B is a material constant and is determined by the composition and impurity level of the material; GS is grain size and icorr is the corrosion rate). Corrosion resistance can be linearly enhanced by reducing the grain size. It has been reported that the reason why grain refinement causes a decreased corrosion rate is because of the improved passive film. A high grain boundary density promotes a better oxide film conduction rate on surfaces with low to passive corrosion rates and therefore a fine grain structure is more corrosion resistant.124, 125 Song and StJohn 126 indicated that the skin of the die-cast AZ91D alloy exhibits better corrosion performance than the interior, because of the more continuous Mg17Al12 phase formed around finer α-Mg grains. If the grains are small and the volume fraction of the Mg17Al12 phase is not too low, then the Mg17Al12 phase forms continuously like a net, and is difficult to undercut because corrosion development cannot easily progress through numerous Mg17Al12 precipitates. The Mg17Al12 phase is exposed and the α-Mg phase corrodes preferentially. Eventually, the final surface of the sample has large amounts of Mg17Al12 which are more corrosion resistant than the α-Mg phase, thus the corrosion resistance is enhanced.91, 127 ...
... 122 proposed that the corrosion rate increases as the logarithm of average grain size increases in pure Mg. Ralston et al.123 also described a relationship between corrosion rate and grain size: icorr=(A)+(B)·GS﹣0.5 (where A is a constant and a function of the environment; B is a material constant and is determined by the composition and impurity level of the material; GS is grain size and icorr is the corrosion rate). Corrosion resistance can be linearly enhanced by reducing the grain size. It has been reported that the reason why grain refinement causes a decreased corrosion rate is because of the improved passive film. A high grain boundary density promotes a better oxide film conduction rate on surfaces with low to passive corrosion rates and therefore a fine grain structure is more corrosion resistant.124, 125 Song and StJohn 126 indicated that the skin of the die-cast AZ91D alloy exhibits better corrosion performance than the interior, because of the more continuous Mg17Al12 phase formed around finer α-Mg grains. If the grains are small and the volume fraction of the Mg17Al12 phase is not too low, then the Mg17Al12 phase forms continuously like a net, and is difficult to undercut because corrosion development cannot easily progress through numerous Mg17Al12 precipitates. The Mg17Al12 phase is exposed and the α-Mg phase corrodes preferentially. Eventually, the final surface of the sample has large amounts of Mg17Al12 which are more corrosion resistant than the α-Mg phase, thus the corrosion resistance is enhanced.91, 127 ...
Revealing the relationship between grain size and corrosion rate of metals
1
2010
... The corrosion behaviour of Mg alloys is closely related to their grain size. Grain refinement is an effective way to improve the corrosion performance of Mg alloys.48, 119-122 For example, Lu et al.111 found that the bio-corrosion rate of Mg-3Zn-0.3Ca is a function of grain size and the volume fraction of secondary phase. Birbilis et al.122 proposed that the corrosion rate increases as the logarithm of average grain size increases in pure Mg. Ralston et al.123 also described a relationship between corrosion rate and grain size: icorr=(A)+(B)·GS﹣0.5 (where A is a constant and a function of the environment; B is a material constant and is determined by the composition and impurity level of the material; GS is grain size and icorr is the corrosion rate). Corrosion resistance can be linearly enhanced by reducing the grain size. It has been reported that the reason why grain refinement causes a decreased corrosion rate is because of the improved passive film. A high grain boundary density promotes a better oxide film conduction rate on surfaces with low to passive corrosion rates and therefore a fine grain structure is more corrosion resistant.124, 125 Song and StJohn 126 indicated that the skin of the die-cast AZ91D alloy exhibits better corrosion performance than the interior, because of the more continuous Mg17Al12 phase formed around finer α-Mg grains. If the grains are small and the volume fraction of the Mg17Al12 phase is not too low, then the Mg17Al12 phase forms continuously like a net, and is difficult to undercut because corrosion development cannot easily progress through numerous Mg17Al12 precipitates. The Mg17Al12 phase is exposed and the α-Mg phase corrodes preferentially. Eventually, the final surface of the sample has large amounts of Mg17Al12 which are more corrosion resistant than the α-Mg phase, thus the corrosion resistance is enhanced.91, 127 ...
Corrosion of pure Mg as a function of grain size and processing route
1
2008
... The corrosion behaviour of Mg alloys is closely related to their grain size. Grain refinement is an effective way to improve the corrosion performance of Mg alloys.48, 119-122 For example, Lu et al.111 found that the bio-corrosion rate of Mg-3Zn-0.3Ca is a function of grain size and the volume fraction of secondary phase. Birbilis et al.122 proposed that the corrosion rate increases as the logarithm of average grain size increases in pure Mg. Ralston et al.123 also described a relationship between corrosion rate and grain size: icorr=(A)+(B)·GS﹣0.5 (where A is a constant and a function of the environment; B is a material constant and is determined by the composition and impurity level of the material; GS is grain size and icorr is the corrosion rate). Corrosion resistance can be linearly enhanced by reducing the grain size. It has been reported that the reason why grain refinement causes a decreased corrosion rate is because of the improved passive film. A high grain boundary density promotes a better oxide film conduction rate on surfaces with low to passive corrosion rates and therefore a fine grain structure is more corrosion resistant.124, 125 Song and StJohn 126 indicated that the skin of the die-cast AZ91D alloy exhibits better corrosion performance than the interior, because of the more continuous Mg17Al12 phase formed around finer α-Mg grains. If the grains are small and the volume fraction of the Mg17Al12 phase is not too low, then the Mg17Al12 phase forms continuously like a net, and is difficult to undercut because corrosion development cannot easily progress through numerous Mg17Al12 precipitates. The Mg17Al12 phase is exposed and the α-Mg phase corrodes preferentially. Eventually, the final surface of the sample has large amounts of Mg17Al12 which are more corrosion resistant than the α-Mg phase, thus the corrosion resistance is enhanced.91, 127 ...
Corrosion behaviour of friction stir welded AZ31B Mg in 3•5%NaCl solution
1
2007
... The corrosion behaviour of Mg alloys is closely related to their grain size. Grain refinement is an effective way to improve the corrosion performance of Mg alloys.48, 119-122 For example, Lu et al.111 found that the bio-corrosion rate of Mg-3Zn-0.3Ca is a function of grain size and the volume fraction of secondary phase. Birbilis et al.122 proposed that the corrosion rate increases as the logarithm of average grain size increases in pure Mg. Ralston et al.123 also described a relationship between corrosion rate and grain size: icorr=(A)+(B)·GS﹣0.5 (where A is a constant and a function of the environment; B is a material constant and is determined by the composition and impurity level of the material; GS is grain size and icorr is the corrosion rate). Corrosion resistance can be linearly enhanced by reducing the grain size. It has been reported that the reason why grain refinement causes a decreased corrosion rate is because of the improved passive film. A high grain boundary density promotes a better oxide film conduction rate on surfaces with low to passive corrosion rates and therefore a fine grain structure is more corrosion resistant.124, 125 Song and StJohn 126 indicated that the skin of the die-cast AZ91D alloy exhibits better corrosion performance than the interior, because of the more continuous Mg17Al12 phase formed around finer α-Mg grains. If the grains are small and the volume fraction of the Mg17Al12 phase is not too low, then the Mg17Al12 phase forms continuously like a net, and is difficult to undercut because corrosion development cannot easily progress through numerous Mg17Al12 precipitates. The Mg17Al12 phase is exposed and the α-Mg phase corrodes preferentially. Eventually, the final surface of the sample has large amounts of Mg17Al12 which are more corrosion resistant than the α-Mg phase, thus the corrosion resistance is enhanced.91, 127 ...
The effect of zirconium grain refinement on the corrosion behaviour of magnesium-rare earth alloy MEZ
2
2002
... The corrosion behaviour of Mg alloys is closely related to their grain size. Grain refinement is an effective way to improve the corrosion performance of Mg alloys.48, 119-122 For example, Lu et al.111 found that the bio-corrosion rate of Mg-3Zn-0.3Ca is a function of grain size and the volume fraction of secondary phase. Birbilis et al.122 proposed that the corrosion rate increases as the logarithm of average grain size increases in pure Mg. Ralston et al.123 also described a relationship between corrosion rate and grain size: icorr=(A)+(B)·GS﹣0.5 (where A is a constant and a function of the environment; B is a material constant and is determined by the composition and impurity level of the material; GS is grain size and icorr is the corrosion rate). Corrosion resistance can be linearly enhanced by reducing the grain size. It has been reported that the reason why grain refinement causes a decreased corrosion rate is because of the improved passive film. A high grain boundary density promotes a better oxide film conduction rate on surfaces with low to passive corrosion rates and therefore a fine grain structure is more corrosion resistant.124, 125 Song and StJohn 126 indicated that the skin of the die-cast AZ91D alloy exhibits better corrosion performance than the interior, because of the more continuous Mg17Al12 phase formed around finer α-Mg grains. If the grains are small and the volume fraction of the Mg17Al12 phase is not too low, then the Mg17Al12 phase forms continuously like a net, and is difficult to undercut because corrosion development cannot easily progress through numerous Mg17Al12 precipitates. The Mg17Al12 phase is exposed and the α-Mg phase corrodes preferentially. Eventually, the final surface of the sample has large amounts of Mg17Al12 which are more corrosion resistant than the α-Mg phase, thus the corrosion resistance is enhanced.91, 127 ...
... Second phases have a significant impact on the performance of Mg alloys.128, 129 A homogenous microstructure is desirable, because a difference in corrosion potential between the α-Mg and the second phase causes micro-galvanic corrosion. In AZ alloys, the Mg17Al12 phase (﹣1.20 V) is nobler than the α-Mg matrix (﹣1.65 V)46 and therefore acts as a cathode and aggravates the corrosion of Mg.91, 130 Some researchers have proposed that the Mg17Al12 phase can act as a corrosion barrier and have a positive effect on corrosion resistance.128, 129, 131 The fraction and distribution of Mg17Al12 phases are important factors in determining which effect dominates. A finely- and continuously-distributed β-phase serves as a corrosion barrier and inhibits corrosion;119 otherwise, the β-phase promotes corrosion. Song et al.126 proposed that more continuous second phases can benefit the corrosion resistance of the Mg-RE-Zr alloy (MEZ alloy). The morphology of the second phase also affects the corrosion behaviour of Mg alloys. Srinivasan et al.132 reported that Mg with a coarse Chinese script Mg2Si phase shows a weaker corrosion performance than that with evenly-distributed polygonal-shaped Mg2Si phases. The reduction and refinement of Mg2Si phases also lead to better corrosion behaviour of Mg-Si(-Ca) alloys.91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
Recent progress in corrosion and protection of magnesium alloys
1
2005
... The corrosion behaviour of Mg alloys is closely related to their grain size. Grain refinement is an effective way to improve the corrosion performance of Mg alloys.48, 119-122 For example, Lu et al.111 found that the bio-corrosion rate of Mg-3Zn-0.3Ca is a function of grain size and the volume fraction of secondary phase. Birbilis et al.122 proposed that the corrosion rate increases as the logarithm of average grain size increases in pure Mg. Ralston et al.123 also described a relationship between corrosion rate and grain size: icorr=(A)+(B)·GS﹣0.5 (where A is a constant and a function of the environment; B is a material constant and is determined by the composition and impurity level of the material; GS is grain size and icorr is the corrosion rate). Corrosion resistance can be linearly enhanced by reducing the grain size. It has been reported that the reason why grain refinement causes a decreased corrosion rate is because of the improved passive film. A high grain boundary density promotes a better oxide film conduction rate on surfaces with low to passive corrosion rates and therefore a fine grain structure is more corrosion resistant.124, 125 Song and StJohn 126 indicated that the skin of the die-cast AZ91D alloy exhibits better corrosion performance than the interior, because of the more continuous Mg17Al12 phase formed around finer α-Mg grains. If the grains are small and the volume fraction of the Mg17Al12 phase is not too low, then the Mg17Al12 phase forms continuously like a net, and is difficult to undercut because corrosion development cannot easily progress through numerous Mg17Al12 precipitates. The Mg17Al12 phase is exposed and the α-Mg phase corrodes preferentially. Eventually, the final surface of the sample has large amounts of Mg17Al12 which are more corrosion resistant than the α-Mg phase, thus the corrosion resistance is enhanced.91, 127 ...
The role of Mg17Al12 phase in the corrosion of Mg alloy AZ91
2
1989
... Second phases have a significant impact on the performance of Mg alloys.128, 129 A homogenous microstructure is desirable, because a difference in corrosion potential between the α-Mg and the second phase causes micro-galvanic corrosion. In AZ alloys, the Mg17Al12 phase (﹣1.20 V) is nobler than the α-Mg matrix (﹣1.65 V)46 and therefore acts as a cathode and aggravates the corrosion of Mg.91, 130 Some researchers have proposed that the Mg17Al12 phase can act as a corrosion barrier and have a positive effect on corrosion resistance.128, 129, 131 The fraction and distribution of Mg17Al12 phases are important factors in determining which effect dominates. A finely- and continuously-distributed β-phase serves as a corrosion barrier and inhibits corrosion;119 otherwise, the β-phase promotes corrosion. Song et al.126 proposed that more continuous second phases can benefit the corrosion resistance of the Mg-RE-Zr alloy (MEZ alloy). The morphology of the second phase also affects the corrosion behaviour of Mg alloys. Srinivasan et al.132 reported that Mg with a coarse Chinese script Mg2Si phase shows a weaker corrosion performance than that with evenly-distributed polygonal-shaped Mg2Si phases. The reduction and refinement of Mg2Si phases also lead to better corrosion behaviour of Mg-Si(-Ca) alloys.91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
... 128, 129, 131 The fraction and distribution of Mg17Al12 phases are important factors in determining which effect dominates. A finely- and continuously-distributed β-phase serves as a corrosion barrier and inhibits corrosion;119 otherwise, the β-phase promotes corrosion. Song et al.126 proposed that more continuous second phases can benefit the corrosion resistance of the Mg-RE-Zr alloy (MEZ alloy). The morphology of the second phase also affects the corrosion behaviour of Mg alloys. Srinivasan et al.132 reported that Mg with a coarse Chinese script Mg2Si phase shows a weaker corrosion performance than that with evenly-distributed polygonal-shaped Mg2Si phases. The reduction and refinement of Mg2Si phases also lead to better corrosion behaviour of Mg-Si(-Ca) alloys.91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
Influence of homogenization and artificial aging heat treatments on corrosion behavior of Mg-Al alloys
2
1993
... Second phases have a significant impact on the performance of Mg alloys.128, 129 A homogenous microstructure is desirable, because a difference in corrosion potential between the α-Mg and the second phase causes micro-galvanic corrosion. In AZ alloys, the Mg17Al12 phase (﹣1.20 V) is nobler than the α-Mg matrix (﹣1.65 V)46 and therefore acts as a cathode and aggravates the corrosion of Mg.91, 130 Some researchers have proposed that the Mg17Al12 phase can act as a corrosion barrier and have a positive effect on corrosion resistance.128, 129, 131 The fraction and distribution of Mg17Al12 phases are important factors in determining which effect dominates. A finely- and continuously-distributed β-phase serves as a corrosion barrier and inhibits corrosion;119 otherwise, the β-phase promotes corrosion. Song et al.126 proposed that more continuous second phases can benefit the corrosion resistance of the Mg-RE-Zr alloy (MEZ alloy). The morphology of the second phase also affects the corrosion behaviour of Mg alloys. Srinivasan et al.132 reported that Mg with a coarse Chinese script Mg2Si phase shows a weaker corrosion performance than that with evenly-distributed polygonal-shaped Mg2Si phases. The reduction and refinement of Mg2Si phases also lead to better corrosion behaviour of Mg-Si(-Ca) alloys.91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
... , 129, 131 The fraction and distribution of Mg17Al12 phases are important factors in determining which effect dominates. A finely- and continuously-distributed β-phase serves as a corrosion barrier and inhibits corrosion;119 otherwise, the β-phase promotes corrosion. Song et al.126 proposed that more continuous second phases can benefit the corrosion resistance of the Mg-RE-Zr alloy (MEZ alloy). The morphology of the second phase also affects the corrosion behaviour of Mg alloys. Srinivasan et al.132 reported that Mg with a coarse Chinese script Mg2Si phase shows a weaker corrosion performance than that with evenly-distributed polygonal-shaped Mg2Si phases. The reduction and refinement of Mg2Si phases also lead to better corrosion behaviour of Mg-Si(-Ca) alloys.91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
Corrosion behaviour of magnesium/aluminium alloys in 3.5wt.% NaCl
1
2008
... Second phases have a significant impact on the performance of Mg alloys.128, 129 A homogenous microstructure is desirable, because a difference in corrosion potential between the α-Mg and the second phase causes micro-galvanic corrosion. In AZ alloys, the Mg17Al12 phase (﹣1.20 V) is nobler than the α-Mg matrix (﹣1.65 V)46 and therefore acts as a cathode and aggravates the corrosion of Mg.91, 130 Some researchers have proposed that the Mg17Al12 phase can act as a corrosion barrier and have a positive effect on corrosion resistance.128, 129, 131 The fraction and distribution of Mg17Al12 phases are important factors in determining which effect dominates. A finely- and continuously-distributed β-phase serves as a corrosion barrier and inhibits corrosion;119 otherwise, the β-phase promotes corrosion. Song et al.126 proposed that more continuous second phases can benefit the corrosion resistance of the Mg-RE-Zr alloy (MEZ alloy). The morphology of the second phase also affects the corrosion behaviour of Mg alloys. Srinivasan et al.132 reported that Mg with a coarse Chinese script Mg2Si phase shows a weaker corrosion performance than that with evenly-distributed polygonal-shaped Mg2Si phases. The reduction and refinement of Mg2Si phases also lead to better corrosion behaviour of Mg-Si(-Ca) alloys.91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
Corrosion resistant magnesium alloys
1
1995
... Second phases have a significant impact on the performance of Mg alloys.128, 129 A homogenous microstructure is desirable, because a difference in corrosion potential between the α-Mg and the second phase causes micro-galvanic corrosion. In AZ alloys, the Mg17Al12 phase (﹣1.20 V) is nobler than the α-Mg matrix (﹣1.65 V)46 and therefore acts as a cathode and aggravates the corrosion of Mg.91, 130 Some researchers have proposed that the Mg17Al12 phase can act as a corrosion barrier and have a positive effect on corrosion resistance.128, 129, 131 The fraction and distribution of Mg17Al12 phases are important factors in determining which effect dominates. A finely- and continuously-distributed β-phase serves as a corrosion barrier and inhibits corrosion;119 otherwise, the β-phase promotes corrosion. Song et al.126 proposed that more continuous second phases can benefit the corrosion resistance of the Mg-RE-Zr alloy (MEZ alloy). The morphology of the second phase also affects the corrosion behaviour of Mg alloys. Srinivasan et al.132 reported that Mg with a coarse Chinese script Mg2Si phase shows a weaker corrosion performance than that with evenly-distributed polygonal-shaped Mg2Si phases. The reduction and refinement of Mg2Si phases also lead to better corrosion behaviour of Mg-Si(-Ca) alloys.91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
Influence of Si and Sb additions on the corrosion behavior of AZ91 magnesium alloy
1
2007
... Second phases have a significant impact on the performance of Mg alloys.128, 129 A homogenous microstructure is desirable, because a difference in corrosion potential between the α-Mg and the second phase causes micro-galvanic corrosion. In AZ alloys, the Mg17Al12 phase (﹣1.20 V) is nobler than the α-Mg matrix (﹣1.65 V)46 and therefore acts as a cathode and aggravates the corrosion of Mg.91, 130 Some researchers have proposed that the Mg17Al12 phase can act as a corrosion barrier and have a positive effect on corrosion resistance.128, 129, 131 The fraction and distribution of Mg17Al12 phases are important factors in determining which effect dominates. A finely- and continuously-distributed β-phase serves as a corrosion barrier and inhibits corrosion;119 otherwise, the β-phase promotes corrosion. Song et al.126 proposed that more continuous second phases can benefit the corrosion resistance of the Mg-RE-Zr alloy (MEZ alloy). The morphology of the second phase also affects the corrosion behaviour of Mg alloys. Srinivasan et al.132 reported that Mg with a coarse Chinese script Mg2Si phase shows a weaker corrosion performance than that with evenly-distributed polygonal-shaped Mg2Si phases. The reduction and refinement of Mg2Si phases also lead to better corrosion behaviour of Mg-Si(-Ca) alloys.91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
A promising biodegradable magnesium alloy suitable for clinical vascular stent application
3
2017
... Second phases have a significant impact on the performance of Mg alloys.128, 129 A homogenous microstructure is desirable, because a difference in corrosion potential between the α-Mg and the second phase causes micro-galvanic corrosion. In AZ alloys, the Mg17Al12 phase (﹣1.20 V) is nobler than the α-Mg matrix (﹣1.65 V)46 and therefore acts as a cathode and aggravates the corrosion of Mg.91, 130 Some researchers have proposed that the Mg17Al12 phase can act as a corrosion barrier and have a positive effect on corrosion resistance.128, 129, 131 The fraction and distribution of Mg17Al12 phases are important factors in determining which effect dominates. A finely- and continuously-distributed β-phase serves as a corrosion barrier and inhibits corrosion;119 otherwise, the β-phase promotes corrosion. Song et al.126 proposed that more continuous second phases can benefit the corrosion resistance of the Mg-RE-Zr alloy (MEZ alloy). The morphology of the second phase also affects the corrosion behaviour of Mg alloys. Srinivasan et al.132 reported that Mg with a coarse Chinese script Mg2Si phase shows a weaker corrosion performance than that with evenly-distributed polygonal-shaped Mg2Si phases. The reduction and refinement of Mg2Si phases also lead to better corrosion behaviour of Mg-Si(-Ca) alloys.91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
... 133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
... Secondly, in order to achieve suitable mechanical properties (UTS: ~200 MPa, elongation: ~20%) and service life-time (3-4 months for orthopaedic application),133 the alloying design, processing history, heat treatment and impurity control (like Fe, Ni, Cu and Co) need to be carefully considered and tailored properly. For orthopaedic applications, the fatigue-corrosion behaviour in an aqueous environment also must be taken into account. The mechanical properties can be improved by various strengthening mechanisms, such as grain refinement strengthening, solid solution strengthening and precipitate strengthening. ...
Effects of extrusion and heat treatment on the mechanical properties and biocorrosion behaviors of a Mg-Nd-Zn-Zr alloy
1
2012
... Second phases have a significant impact on the performance of Mg alloys.128, 129 A homogenous microstructure is desirable, because a difference in corrosion potential between the α-Mg and the second phase causes micro-galvanic corrosion. In AZ alloys, the Mg17Al12 phase (﹣1.20 V) is nobler than the α-Mg matrix (﹣1.65 V)46 and therefore acts as a cathode and aggravates the corrosion of Mg.91, 130 Some researchers have proposed that the Mg17Al12 phase can act as a corrosion barrier and have a positive effect on corrosion resistance.128, 129, 131 The fraction and distribution of Mg17Al12 phases are important factors in determining which effect dominates. A finely- and continuously-distributed β-phase serves as a corrosion barrier and inhibits corrosion;119 otherwise, the β-phase promotes corrosion. Song et al.126 proposed that more continuous second phases can benefit the corrosion resistance of the Mg-RE-Zr alloy (MEZ alloy). The morphology of the second phase also affects the corrosion behaviour of Mg alloys. Srinivasan et al.132 reported that Mg with a coarse Chinese script Mg2Si phase shows a weaker corrosion performance than that with evenly-distributed polygonal-shaped Mg2Si phases. The reduction and refinement of Mg2Si phases also lead to better corrosion behaviour of Mg-Si(-Ca) alloys.91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
Comparison of biodegradable behaviors of AZ31 and Mg-Nd-Zn-Zr alloys in Hank’s physiological solution
1
2012
... Second phases have a significant impact on the performance of Mg alloys.128, 129 A homogenous microstructure is desirable, because a difference in corrosion potential between the α-Mg and the second phase causes micro-galvanic corrosion. In AZ alloys, the Mg17Al12 phase (﹣1.20 V) is nobler than the α-Mg matrix (﹣1.65 V)46 and therefore acts as a cathode and aggravates the corrosion of Mg.91, 130 Some researchers have proposed that the Mg17Al12 phase can act as a corrosion barrier and have a positive effect on corrosion resistance.128, 129, 131 The fraction and distribution of Mg17Al12 phases are important factors in determining which effect dominates. A finely- and continuously-distributed β-phase serves as a corrosion barrier and inhibits corrosion;119 otherwise, the β-phase promotes corrosion. Song et al.126 proposed that more continuous second phases can benefit the corrosion resistance of the Mg-RE-Zr alloy (MEZ alloy). The morphology of the second phase also affects the corrosion behaviour of Mg alloys. Srinivasan et al.132 reported that Mg with a coarse Chinese script Mg2Si phase shows a weaker corrosion performance than that with evenly-distributed polygonal-shaped Mg2Si phases. The reduction and refinement of Mg2Si phases also lead to better corrosion behaviour of Mg-Si(-Ca) alloys.91 The rod-shaped nano-scale β’www1 precipitates which form during aging strengthen the Mg-3Zn alloy, but decrease its corrosion resistance.101 Mao et al.133 have reported that different thermal-mechanical processing treatments result in differences in mechanical and bio-corrosion performance. The yield strength (YS), ultimate tensile strength (UTS) and elongation of Mg-3.1Nd-0.2Zn-0.4Zr (JDBM) alloy significantly improved after hot extrusion, thanks mainly to precipitation strengthening.94, 134 The corrosion rate of extruded JDBM (0.13 mm/year) was much lower than that of AZ91 (1.02 mm/year), because of a homogeneous distribution of nano-scaled Mg12Nd phase.135 Mg-2.2Nd-0.1Zn-0.4Zr (JDBM-2) alloy after double extrusion showed a high strength (276 MPa) and elongation (34%) and a good corrosion rate (0.37 mm/year) in artificial plasma for 120 hours, caused by the presence of nanoparticles and by grain refinement.133 The finely dispersed nano-scale precipitates not only improve the mechanical properties but also lead to homogeneous degradation and a reduced corrosion rate. ...
DC and AC polarisation study on magnesium alloys Influence of the mechanical deformation
1
2002
... Several researchers report that twins, texture and dislocations all have influences on the corrosion performance. Aung and Zhou120 reported that the existence of twins can accelerate the corrosion of Mg alloys. After equal channel angular extrusion, a higher density of dislocations and twins appeared and a more severe dissolution of the anode resulted.121 Andrei et al.136 reported that the equilibrium potential in the vicinity of the dislocations is locally reduced, thus causing accelerated dissolution of the anode. According to Xin et al.137 extruded AZ31 sheet showed better corrosion resistance because of the initial basal texture. Schmutz et al.138 reported that filaments of corrosion propagated at twin boundaries; this corrosion took place on a plane near the basal plane and then propagated down the prismatic planes. ...
Effect of microstructure and texture on corrosion resistance of magnesium alloy
1
2009
... Several researchers report that twins, texture and dislocations all have influences on the corrosion performance. Aung and Zhou120 reported that the existence of twins can accelerate the corrosion of Mg alloys. After equal channel angular extrusion, a higher density of dislocations and twins appeared and a more severe dissolution of the anode resulted.121 Andrei et al.136 reported that the equilibrium potential in the vicinity of the dislocations is locally reduced, thus causing accelerated dissolution of the anode. According to Xin et al.137 extruded AZ31 sheet showed better corrosion resistance because of the initial basal texture. Schmutz et al.138 reported that filaments of corrosion propagated at twin boundaries; this corrosion took place on a plane near the basal plane and then propagated down the prismatic planes. ...
Influence of dichromate ions on corrosion processes on pure magnesium
1
2003
... Several researchers report that twins, texture and dislocations all have influences on the corrosion performance. Aung and Zhou120 reported that the existence of twins can accelerate the corrosion of Mg alloys. After equal channel angular extrusion, a higher density of dislocations and twins appeared and a more severe dissolution of the anode resulted.121 Andrei et al.136 reported that the equilibrium potential in the vicinity of the dislocations is locally reduced, thus causing accelerated dissolution of the anode. According to Xin et al.137 extruded AZ31 sheet showed better corrosion resistance because of the initial basal texture. Schmutz et al.138 reported that filaments of corrosion propagated at twin boundaries; this corrosion took place on a plane near the basal plane and then propagated down the prismatic planes. ...
Corrosion of, and cellular responses to Mg-Zn-Ca bulk metallic glasses
2
2010
... Mg-based BMGs display a uniform corrosion performance due to their single phase structure and chemical homogeneity. An increased corrosion resistance, uniform corrosion morphology and better cytocompatibility of Mg66Zn30Ca4 BMG have been reported by Gu et al.139 The glassy Mg60+xZn35﹣xCa5 (0 ≤ x ≤ 7) alloys exhibited a distinct reduction in hydrogen evolution.140 A wide range of in vitro electrochemical corrosion rates of BMGs has been shown, for example 11.2 µA/cm2 for Mg70Zn25Ca5139 and0.02 µA/cm2 for Mg65Cu20Y10Zn5.141 The Mg67Zn28Ca5 BMG shows good tensile strength: 675﹣894 MPa,142 while the Mg66Zn30Ca4 BMG shows good compressive strength: 716﹣854 MPa.140 However, the manufacturability and application of BMGs is limited by their glass-forming ability which is very sensitive to the fabrication methods and the purity of the components. Moreover, the brittleness of BMGs needs to be carefully considered: they normally fail without, or with limited, macro-plasticity. Nevertheless, significant elongations of BMGs have been reported: 1.6% for Mg65Cu15Ag10Y2Gd8,143 0.5% for Mg63Cu16.8Ag11.2Er10144 and 0.9% for Mg65Cu7.5Ag5Ni7.5Gd5.143 The structural relaxation at 20°C and 37°C for Mg95﹣xZnxCa5 BMG has been examined. The relaxation time increased from 10 to 30 days at 20°C, combined with a dramatic reduced hydrogen evolution.145 Yu et al.146 reported that the addition of Yb (2at% and 4at%) significantly improved the ductility of MgZnCa BMGs. ...
... 139 and0.02 µA/cm2 for Mg65Cu20Y10Zn5.141 The Mg67Zn28Ca5 BMG shows good tensile strength: 675﹣894 MPa,142 while the Mg66Zn30Ca4 BMG shows good compressive strength: 716﹣854 MPa.140 However, the manufacturability and application of BMGs is limited by their glass-forming ability which is very sensitive to the fabrication methods and the purity of the components. Moreover, the brittleness of BMGs needs to be carefully considered: they normally fail without, or with limited, macro-plasticity. Nevertheless, significant elongations of BMGs have been reported: 1.6% for Mg65Cu15Ag10Y2Gd8,143 0.5% for Mg63Cu16.8Ag11.2Er10144 and 0.9% for Mg65Cu7.5Ag5Ni7.5Gd5.143 The structural relaxation at 20°C and 37°C for Mg95﹣xZnxCa5 BMG has been examined. The relaxation time increased from 10 to 30 days at 20°C, combined with a dramatic reduced hydrogen evolution.145 Yu et al.146 reported that the addition of Yb (2at% and 4at%) significantly improved the ductility of MgZnCa BMGs. ...
MgZnCa glasses without clinically observable hydrogen evolution for biodegradable implants
2
2009
... Mg-based BMGs display a uniform corrosion performance due to their single phase structure and chemical homogeneity. An increased corrosion resistance, uniform corrosion morphology and better cytocompatibility of Mg66Zn30Ca4 BMG have been reported by Gu et al.139 The glassy Mg60+xZn35﹣xCa5 (0 ≤ x ≤ 7) alloys exhibited a distinct reduction in hydrogen evolution.140 A wide range of in vitro electrochemical corrosion rates of BMGs has been shown, for example 11.2 µA/cm2 for Mg70Zn25Ca5139 and0.02 µA/cm2 for Mg65Cu20Y10Zn5.141 The Mg67Zn28Ca5 BMG shows good tensile strength: 675﹣894 MPa,142 while the Mg66Zn30Ca4 BMG shows good compressive strength: 716﹣854 MPa.140 However, the manufacturability and application of BMGs is limited by their glass-forming ability which is very sensitive to the fabrication methods and the purity of the components. Moreover, the brittleness of BMGs needs to be carefully considered: they normally fail without, or with limited, macro-plasticity. Nevertheless, significant elongations of BMGs have been reported: 1.6% for Mg65Cu15Ag10Y2Gd8,143 0.5% for Mg63Cu16.8Ag11.2Er10144 and 0.9% for Mg65Cu7.5Ag5Ni7.5Gd5.143 The structural relaxation at 20°C and 37°C for Mg95﹣xZnxCa5 BMG has been examined. The relaxation time increased from 10 to 30 days at 20°C, combined with a dramatic reduced hydrogen evolution.145 Yu et al.146 reported that the addition of Yb (2at% and 4at%) significantly improved the ductility of MgZnCa BMGs. ...
... 140 However, the manufacturability and application of BMGs is limited by their glass-forming ability which is very sensitive to the fabrication methods and the purity of the components. Moreover, the brittleness of BMGs needs to be carefully considered: they normally fail without, or with limited, macro-plasticity. Nevertheless, significant elongations of BMGs have been reported: 1.6% for Mg65Cu15Ag10Y2Gd8,143 0.5% for Mg63Cu16.8Ag11.2Er10144 and 0.9% for Mg65Cu7.5Ag5Ni7.5Gd5.143 The structural relaxation at 20°C and 37°C for Mg95﹣xZnxCa5 BMG has been examined. The relaxation time increased from 10 to 30 days at 20°C, combined with a dramatic reduced hydrogen evolution.145 Yu et al.146 reported that the addition of Yb (2at% and 4at%) significantly improved the ductility of MgZnCa BMGs. ...
Mg-based bulk metallic glass composite with high bio-corrosion resistance and excellent mechanical properties
1
2012
... Mg-based BMGs display a uniform corrosion performance due to their single phase structure and chemical homogeneity. An increased corrosion resistance, uniform corrosion morphology and better cytocompatibility of Mg66Zn30Ca4 BMG have been reported by Gu et al.139 The glassy Mg60+xZn35﹣xCa5 (0 ≤ x ≤ 7) alloys exhibited a distinct reduction in hydrogen evolution.140 A wide range of in vitro electrochemical corrosion rates of BMGs has been shown, for example 11.2 µA/cm2 for Mg70Zn25Ca5139 and0.02 µA/cm2 for Mg65Cu20Y10Zn5.141 The Mg67Zn28Ca5 BMG shows good tensile strength: 675﹣894 MPa,142 while the Mg66Zn30Ca4 BMG shows good compressive strength: 716﹣854 MPa.140 However, the manufacturability and application of BMGs is limited by their glass-forming ability which is very sensitive to the fabrication methods and the purity of the components. Moreover, the brittleness of BMGs needs to be carefully considered: they normally fail without, or with limited, macro-plasticity. Nevertheless, significant elongations of BMGs have been reported: 1.6% for Mg65Cu15Ag10Y2Gd8,143 0.5% for Mg63Cu16.8Ag11.2Er10144 and 0.9% for Mg65Cu7.5Ag5Ni7.5Gd5.143 The structural relaxation at 20°C and 37°C for Mg95﹣xZnxCa5 BMG has been examined. The relaxation time increased from 10 to 30 days at 20°C, combined with a dramatic reduced hydrogen evolution.145 Yu et al.146 reported that the addition of Yb (2at% and 4at%) significantly improved the ductility of MgZnCa BMGs. ...
Tensile properties of glassy MgZnCa wires and reliability analysis using Weibull statistics
1
2009
... Mg-based BMGs display a uniform corrosion performance due to their single phase structure and chemical homogeneity. An increased corrosion resistance, uniform corrosion morphology and better cytocompatibility of Mg66Zn30Ca4 BMG have been reported by Gu et al.139 The glassy Mg60+xZn35﹣xCa5 (0 ≤ x ≤ 7) alloys exhibited a distinct reduction in hydrogen evolution.140 A wide range of in vitro electrochemical corrosion rates of BMGs has been shown, for example 11.2 µA/cm2 for Mg70Zn25Ca5139 and0.02 µA/cm2 for Mg65Cu20Y10Zn5.141 The Mg67Zn28Ca5 BMG shows good tensile strength: 675﹣894 MPa,142 while the Mg66Zn30Ca4 BMG shows good compressive strength: 716﹣854 MPa.140 However, the manufacturability and application of BMGs is limited by their glass-forming ability which is very sensitive to the fabrication methods and the purity of the components. Moreover, the brittleness of BMGs needs to be carefully considered: they normally fail without, or with limited, macro-plasticity. Nevertheless, significant elongations of BMGs have been reported: 1.6% for Mg65Cu15Ag10Y2Gd8,143 0.5% for Mg63Cu16.8Ag11.2Er10144 and 0.9% for Mg65Cu7.5Ag5Ni7.5Gd5.143 The structural relaxation at 20°C and 37°C for Mg95﹣xZnxCa5 BMG has been examined. The relaxation time increased from 10 to 30 days at 20°C, combined with a dramatic reduced hydrogen evolution.145 Yu et al.146 reported that the addition of Yb (2at% and 4at%) significantly improved the ductility of MgZnCa BMGs. ...
Bulk glass formation in Mg-Cu-Ag-Y-Gd alloy
2
2004
... Mg-based BMGs display a uniform corrosion performance due to their single phase structure and chemical homogeneity. An increased corrosion resistance, uniform corrosion morphology and better cytocompatibility of Mg66Zn30Ca4 BMG have been reported by Gu et al.139 The glassy Mg60+xZn35﹣xCa5 (0 ≤ x ≤ 7) alloys exhibited a distinct reduction in hydrogen evolution.140 A wide range of in vitro electrochemical corrosion rates of BMGs has been shown, for example 11.2 µA/cm2 for Mg70Zn25Ca5139 and0.02 µA/cm2 for Mg65Cu20Y10Zn5.141 The Mg67Zn28Ca5 BMG shows good tensile strength: 675﹣894 MPa,142 while the Mg66Zn30Ca4 BMG shows good compressive strength: 716﹣854 MPa.140 However, the manufacturability and application of BMGs is limited by their glass-forming ability which is very sensitive to the fabrication methods and the purity of the components. Moreover, the brittleness of BMGs needs to be carefully considered: they normally fail without, or with limited, macro-plasticity. Nevertheless, significant elongations of BMGs have been reported: 1.6% for Mg65Cu15Ag10Y2Gd8,143 0.5% for Mg63Cu16.8Ag11.2Er10144 and 0.9% for Mg65Cu7.5Ag5Ni7.5Gd5.143 The structural relaxation at 20°C and 37°C for Mg95﹣xZnxCa5 BMG has been examined. The relaxation time increased from 10 to 30 days at 20°C, combined with a dramatic reduced hydrogen evolution.145 Yu et al.146 reported that the addition of Yb (2at% and 4at%) significantly improved the ductility of MgZnCa BMGs. ...
... 143 The structural relaxation at 20°C and 37°C for Mg95﹣xZnxCa5 BMG has been examined. The relaxation time increased from 10 to 30 days at 20°C, combined with a dramatic reduced hydrogen evolution.145 Yu et al.146 reported that the addition of Yb (2at% and 4at%) significantly improved the ductility of MgZnCa BMGs. ...
Mg-Cu-Ag-Er bulk metallic glasses with high glass forming ability and compressive strength
1
2009
... Mg-based BMGs display a uniform corrosion performance due to their single phase structure and chemical homogeneity. An increased corrosion resistance, uniform corrosion morphology and better cytocompatibility of Mg66Zn30Ca4 BMG have been reported by Gu et al.139 The glassy Mg60+xZn35﹣xCa5 (0 ≤ x ≤ 7) alloys exhibited a distinct reduction in hydrogen evolution.140 A wide range of in vitro electrochemical corrosion rates of BMGs has been shown, for example 11.2 µA/cm2 for Mg70Zn25Ca5139 and0.02 µA/cm2 for Mg65Cu20Y10Zn5.141 The Mg67Zn28Ca5 BMG shows good tensile strength: 675﹣894 MPa,142 while the Mg66Zn30Ca4 BMG shows good compressive strength: 716﹣854 MPa.140 However, the manufacturability and application of BMGs is limited by their glass-forming ability which is very sensitive to the fabrication methods and the purity of the components. Moreover, the brittleness of BMGs needs to be carefully considered: they normally fail without, or with limited, macro-plasticity. Nevertheless, significant elongations of BMGs have been reported: 1.6% for Mg65Cu15Ag10Y2Gd8,143 0.5% for Mg63Cu16.8Ag11.2Er10144 and 0.9% for Mg65Cu7.5Ag5Ni7.5Gd5.143 The structural relaxation at 20°C and 37°C for Mg95﹣xZnxCa5 BMG has been examined. The relaxation time increased from 10 to 30 days at 20°C, combined with a dramatic reduced hydrogen evolution.145 Yu et al.146 reported that the addition of Yb (2at% and 4at%) significantly improved the ductility of MgZnCa BMGs. ...
In vivo performance and structural relaxation of biodegradable bone implants made from Mg Zn Ca bulk metallic glasses
1
2012
... Mg-based BMGs display a uniform corrosion performance due to their single phase structure and chemical homogeneity. An increased corrosion resistance, uniform corrosion morphology and better cytocompatibility of Mg66Zn30Ca4 BMG have been reported by Gu et al.139 The glassy Mg60+xZn35﹣xCa5 (0 ≤ x ≤ 7) alloys exhibited a distinct reduction in hydrogen evolution.140 A wide range of in vitro electrochemical corrosion rates of BMGs has been shown, for example 11.2 µA/cm2 for Mg70Zn25Ca5139 and0.02 µA/cm2 for Mg65Cu20Y10Zn5.141 The Mg67Zn28Ca5 BMG shows good tensile strength: 675﹣894 MPa,142 while the Mg66Zn30Ca4 BMG shows good compressive strength: 716﹣854 MPa.140 However, the manufacturability and application of BMGs is limited by their glass-forming ability which is very sensitive to the fabrication methods and the purity of the components. Moreover, the brittleness of BMGs needs to be carefully considered: they normally fail without, or with limited, macro-plasticity. Nevertheless, significant elongations of BMGs have been reported: 1.6% for Mg65Cu15Ag10Y2Gd8,143 0.5% for Mg63Cu16.8Ag11.2Er10144 and 0.9% for Mg65Cu7.5Ag5Ni7.5Gd5.143 The structural relaxation at 20°C and 37°C for Mg95﹣xZnxCa5 BMG has been examined. The relaxation time increased from 10 to 30 days at 20°C, combined with a dramatic reduced hydrogen evolution.145 Yu et al.146 reported that the addition of Yb (2at% and 4at%) significantly improved the ductility of MgZnCa BMGs. ...
Ductile biodegradable Mg-based metallic glasses with excellent biocompatibility
1
2013
... Mg-based BMGs display a uniform corrosion performance due to their single phase structure and chemical homogeneity. An increased corrosion resistance, uniform corrosion morphology and better cytocompatibility of Mg66Zn30Ca4 BMG have been reported by Gu et al.139 The glassy Mg60+xZn35﹣xCa5 (0 ≤ x ≤ 7) alloys exhibited a distinct reduction in hydrogen evolution.140 A wide range of in vitro electrochemical corrosion rates of BMGs has been shown, for example 11.2 µA/cm2 for Mg70Zn25Ca5139 and0.02 µA/cm2 for Mg65Cu20Y10Zn5.141 The Mg67Zn28Ca5 BMG shows good tensile strength: 675﹣894 MPa,142 while the Mg66Zn30Ca4 BMG shows good compressive strength: 716﹣854 MPa.140 However, the manufacturability and application of BMGs is limited by their glass-forming ability which is very sensitive to the fabrication methods and the purity of the components. Moreover, the brittleness of BMGs needs to be carefully considered: they normally fail without, or with limited, macro-plasticity. Nevertheless, significant elongations of BMGs have been reported: 1.6% for Mg65Cu15Ag10Y2Gd8,143 0.5% for Mg63Cu16.8Ag11.2Er10144 and 0.9% for Mg65Cu7.5Ag5Ni7.5Gd5.143 The structural relaxation at 20°C and 37°C for Mg95﹣xZnxCa5 BMG has been examined. The relaxation time increased from 10 to 30 days at 20°C, combined with a dramatic reduced hydrogen evolution.145 Yu et al.146 reported that the addition of Yb (2at% and 4at%) significantly improved the ductility of MgZnCa BMGs. ...
Metallic glasses as structural materials
2
2006
... The fabrication method and processing parameters significantly affect the alloying composition and microstructure of Mg-based BMGs. The current development of Mg-based BMGs for clinical applications is still focused on the forming ability and formation mechanism. A simple fabrication process and production of reasonably large sized BMGs need to be further developed. It has been reported that Mg-based BMGs have higher yield stress than their crystalline counterparts due to the absence of the crystallographically-defined slip systems in polycrystalline metallic materials.147 However the ductility of Mg-based BMGs needs to be further improved because they are extremely brittle. In addition, while some Mg-based BMGs possess good biocompatibility, other Mg-based BMGs contain toxic alloying elements (such as transition metals and RE elements) because of their good glass-forming ability. Thus the alloying design of Mg-based BMGs needs to be carefully tailored. ...
... Note: NA: not applicable. Data are from Gu et al.147 ...
Microstructure, mechanical properties and bio-corrosion evaluation of biodegradable AZ91-FA nanocomposites for biomedical applications
2
2010
... Mg MMCs show a wide range of mechanical and corrosion behaviours because of the wide range of reinforcements and their content, distribution and size. The manufacturing methods are usually powder metallurgy or stir casting. The matrix materials are biomedical Mg alloys such as Mg-Ca, Mg-Al, Mg-Zn and Mg-RE. Calcium phosphate-based ceramics (like calcium polyphosphate, hydroxyapatite and tri-calcium phosphate), calcium, bioactive glass and zinc oxide have all been used to reinforce Mg MMCs. The amount, distribution and size of reinforcements are very important for the mechanical and bio-corrosion properties of Mg MMCs. For example, fluorapatite nanoparticles (up to 20%) have been used to improve the mechanical properties of AZ91/FA MMC.148 Mg/ZnO MMCs (20wt% ZnO nanoparticles) have been prepared using powder metallurgy and confer improved tensile strength, hardness and corrosion resistance but with reduced elongation.149 ZK60/CPP (calcium polyphosphate particles) MMCs have been produced with a compressive strength of 495 MPa.150 Gu et al.151 developed Mg-hydroxyapatite (10wt%, 20wt% and 30wt%) composites using powder metallurgy. Mg/10HA composites showed higher YS, lower UTS and elongation, reduced corrosion resistance and no toxicity. An MMC was fabricated using Mg-2.9Zn-0.7Zr as the matrix and 1wt% nano HA particles as reinforcement; it had a corrosion rate of 0.75 mm/year.152 A nano-sized β-tricalcium phosphate/Mg-3Zn-Ca composite was produced and showed a UTS of 125 MPa and elongation of 2.85%.153 Poly (L-lactic) acid-Mg65Zn30Ca5 composites were studied as potential orthopaedic implant candidates; they showed high corrosion resistance and good antibacterial properties.154 A collagen (10%)-hydroxyapatite (80%)-Mg (10%) composite scaffold was developed as a bone substitute and showed favourable bone healing and regeneration.155 A novel Mg nanocomposite scaffold was fabricated and demonstrated that a Mg cationic microenvironment promotes cell viability and osteogenic differentiation properties in vitro leading to effective bone defect repair.156, 157 ...
... 3) Electrochemical measurement is widely used to measure the in vitro degradation behaviour of Mg alloys. The greatest advantage is that it can be used to obtain the real-time corrosion rate.106, 148, 183-185 Changes in corrosion behaviour can be instantaneously observed. Generally, the Mg sample is used as the working electrode, platinum as the counter electrode and a saturated calomel electrode as the reference electrode. Using this method, more corrosion information can be accessed, such as the relative rates of the anodic and cathodic reactions over a range of potentials.186 A number of investigations indicate that the corrosion rate of Mg alloys measured by electrochemical testing agrees with that by hydrogen evolution and helps to increase the understanding of how corrosion takes place.119, 186, 187 ...
On the corrosion behaviour of newly developed biodegradable Mg-based metal matrix composites produced by in situ reaction
1
2012
... Mg MMCs show a wide range of mechanical and corrosion behaviours because of the wide range of reinforcements and their content, distribution and size. The manufacturing methods are usually powder metallurgy or stir casting. The matrix materials are biomedical Mg alloys such as Mg-Ca, Mg-Al, Mg-Zn and Mg-RE. Calcium phosphate-based ceramics (like calcium polyphosphate, hydroxyapatite and tri-calcium phosphate), calcium, bioactive glass and zinc oxide have all been used to reinforce Mg MMCs. The amount, distribution and size of reinforcements are very important for the mechanical and bio-corrosion properties of Mg MMCs. For example, fluorapatite nanoparticles (up to 20%) have been used to improve the mechanical properties of AZ91/FA MMC.148 Mg/ZnO MMCs (20wt% ZnO nanoparticles) have been prepared using powder metallurgy and confer improved tensile strength, hardness and corrosion resistance but with reduced elongation.149 ZK60/CPP (calcium polyphosphate particles) MMCs have been produced with a compressive strength of 495 MPa.150 Gu et al.151 developed Mg-hydroxyapatite (10wt%, 20wt% and 30wt%) composites using powder metallurgy. Mg/10HA composites showed higher YS, lower UTS and elongation, reduced corrosion resistance and no toxicity. An MMC was fabricated using Mg-2.9Zn-0.7Zr as the matrix and 1wt% nano HA particles as reinforcement; it had a corrosion rate of 0.75 mm/year.152 A nano-sized β-tricalcium phosphate/Mg-3Zn-Ca composite was produced and showed a UTS of 125 MPa and elongation of 2.85%.153 Poly (L-lactic) acid-Mg65Zn30Ca5 composites were studied as potential orthopaedic implant candidates; they showed high corrosion resistance and good antibacterial properties.154 A collagen (10%)-hydroxyapatite (80%)-Mg (10%) composite scaffold was developed as a bone substitute and showed favourable bone healing and regeneration.155 A novel Mg nanocomposite scaffold was fabricated and demonstrated that a Mg cationic microenvironment promotes cell viability and osteogenic differentiation properties in vitro leading to effective bone defect repair.156, 157 ...
The microstructure, mechanical and corrosion properties of calcium polyphosphate reinforced ZK60A magnesium alloy composites
1
2010
... Mg MMCs show a wide range of mechanical and corrosion behaviours because of the wide range of reinforcements and their content, distribution and size. The manufacturing methods are usually powder metallurgy or stir casting. The matrix materials are biomedical Mg alloys such as Mg-Ca, Mg-Al, Mg-Zn and Mg-RE. Calcium phosphate-based ceramics (like calcium polyphosphate, hydroxyapatite and tri-calcium phosphate), calcium, bioactive glass and zinc oxide have all been used to reinforce Mg MMCs. The amount, distribution and size of reinforcements are very important for the mechanical and bio-corrosion properties of Mg MMCs. For example, fluorapatite nanoparticles (up to 20%) have been used to improve the mechanical properties of AZ91/FA MMC.148 Mg/ZnO MMCs (20wt% ZnO nanoparticles) have been prepared using powder metallurgy and confer improved tensile strength, hardness and corrosion resistance but with reduced elongation.149 ZK60/CPP (calcium polyphosphate particles) MMCs have been produced with a compressive strength of 495 MPa.150 Gu et al.151 developed Mg-hydroxyapatite (10wt%, 20wt% and 30wt%) composites using powder metallurgy. Mg/10HA composites showed higher YS, lower UTS and elongation, reduced corrosion resistance and no toxicity. An MMC was fabricated using Mg-2.9Zn-0.7Zr as the matrix and 1wt% nano HA particles as reinforcement; it had a corrosion rate of 0.75 mm/year.152 A nano-sized β-tricalcium phosphate/Mg-3Zn-Ca composite was produced and showed a UTS of 125 MPa and elongation of 2.85%.153 Poly (L-lactic) acid-Mg65Zn30Ca5 composites were studied as potential orthopaedic implant candidates; they showed high corrosion resistance and good antibacterial properties.154 A collagen (10%)-hydroxyapatite (80%)-Mg (10%) composite scaffold was developed as a bone substitute and showed favourable bone healing and regeneration.155 A novel Mg nanocomposite scaffold was fabricated and demonstrated that a Mg cationic microenvironment promotes cell viability and osteogenic differentiation properties in vitro leading to effective bone defect repair.156, 157 ...
Microstructure, mechanical property, bio-corrosion and cytotoxicity evaluations of Mg/HA composites
1
2010
... Mg MMCs show a wide range of mechanical and corrosion behaviours because of the wide range of reinforcements and their content, distribution and size. The manufacturing methods are usually powder metallurgy or stir casting. The matrix materials are biomedical Mg alloys such as Mg-Ca, Mg-Al, Mg-Zn and Mg-RE. Calcium phosphate-based ceramics (like calcium polyphosphate, hydroxyapatite and tri-calcium phosphate), calcium, bioactive glass and zinc oxide have all been used to reinforce Mg MMCs. The amount, distribution and size of reinforcements are very important for the mechanical and bio-corrosion properties of Mg MMCs. For example, fluorapatite nanoparticles (up to 20%) have been used to improve the mechanical properties of AZ91/FA MMC.148 Mg/ZnO MMCs (20wt% ZnO nanoparticles) have been prepared using powder metallurgy and confer improved tensile strength, hardness and corrosion resistance but with reduced elongation.149 ZK60/CPP (calcium polyphosphate particles) MMCs have been produced with a compressive strength of 495 MPa.150 Gu et al.151 developed Mg-hydroxyapatite (10wt%, 20wt% and 30wt%) composites using powder metallurgy. Mg/10HA composites showed higher YS, lower UTS and elongation, reduced corrosion resistance and no toxicity. An MMC was fabricated using Mg-2.9Zn-0.7Zr as the matrix and 1wt% nano HA particles as reinforcement; it had a corrosion rate of 0.75 mm/year.152 A nano-sized β-tricalcium phosphate/Mg-3Zn-Ca composite was produced and showed a UTS of 125 MPa and elongation of 2.85%.153 Poly (L-lactic) acid-Mg65Zn30Ca5 composites were studied as potential orthopaedic implant candidates; they showed high corrosion resistance and good antibacterial properties.154 A collagen (10%)-hydroxyapatite (80%)-Mg (10%) composite scaffold was developed as a bone substitute and showed favourable bone healing and regeneration.155 A novel Mg nanocomposite scaffold was fabricated and demonstrated that a Mg cationic microenvironment promotes cell viability and osteogenic differentiation properties in vitro leading to effective bone defect repair.156, 157 ...
In vitro corrosion resistance and cytocompatibility of nano-hydroxyapatite reinforced Mg-Zn-Zr composites
1
2010
... Mg MMCs show a wide range of mechanical and corrosion behaviours because of the wide range of reinforcements and their content, distribution and size. The manufacturing methods are usually powder metallurgy or stir casting. The matrix materials are biomedical Mg alloys such as Mg-Ca, Mg-Al, Mg-Zn and Mg-RE. Calcium phosphate-based ceramics (like calcium polyphosphate, hydroxyapatite and tri-calcium phosphate), calcium, bioactive glass and zinc oxide have all been used to reinforce Mg MMCs. The amount, distribution and size of reinforcements are very important for the mechanical and bio-corrosion properties of Mg MMCs. For example, fluorapatite nanoparticles (up to 20%) have been used to improve the mechanical properties of AZ91/FA MMC.148 Mg/ZnO MMCs (20wt% ZnO nanoparticles) have been prepared using powder metallurgy and confer improved tensile strength, hardness and corrosion resistance but with reduced elongation.149 ZK60/CPP (calcium polyphosphate particles) MMCs have been produced with a compressive strength of 495 MPa.150 Gu et al.151 developed Mg-hydroxyapatite (10wt%, 20wt% and 30wt%) composites using powder metallurgy. Mg/10HA composites showed higher YS, lower UTS and elongation, reduced corrosion resistance and no toxicity. An MMC was fabricated using Mg-2.9Zn-0.7Zr as the matrix and 1wt% nano HA particles as reinforcement; it had a corrosion rate of 0.75 mm/year.152 A nano-sized β-tricalcium phosphate/Mg-3Zn-Ca composite was produced and showed a UTS of 125 MPa and elongation of 2.85%.153 Poly (L-lactic) acid-Mg65Zn30Ca5 composites were studied as potential orthopaedic implant candidates; they showed high corrosion resistance and good antibacterial properties.154 A collagen (10%)-hydroxyapatite (80%)-Mg (10%) composite scaffold was developed as a bone substitute and showed favourable bone healing and regeneration.155 A novel Mg nanocomposite scaffold was fabricated and demonstrated that a Mg cationic microenvironment promotes cell viability and osteogenic differentiation properties in vitro leading to effective bone defect repair.156, 157 ...
Fabrication of biodegradable nano-sized β-TCP/Mg composite by a novel melt shearing technology
1
2012
... Mg MMCs show a wide range of mechanical and corrosion behaviours because of the wide range of reinforcements and their content, distribution and size. The manufacturing methods are usually powder metallurgy or stir casting. The matrix materials are biomedical Mg alloys such as Mg-Ca, Mg-Al, Mg-Zn and Mg-RE. Calcium phosphate-based ceramics (like calcium polyphosphate, hydroxyapatite and tri-calcium phosphate), calcium, bioactive glass and zinc oxide have all been used to reinforce Mg MMCs. The amount, distribution and size of reinforcements are very important for the mechanical and bio-corrosion properties of Mg MMCs. For example, fluorapatite nanoparticles (up to 20%) have been used to improve the mechanical properties of AZ91/FA MMC.148 Mg/ZnO MMCs (20wt% ZnO nanoparticles) have been prepared using powder metallurgy and confer improved tensile strength, hardness and corrosion resistance but with reduced elongation.149 ZK60/CPP (calcium polyphosphate particles) MMCs have been produced with a compressive strength of 495 MPa.150 Gu et al.151 developed Mg-hydroxyapatite (10wt%, 20wt% and 30wt%) composites using powder metallurgy. Mg/10HA composites showed higher YS, lower UTS and elongation, reduced corrosion resistance and no toxicity. An MMC was fabricated using Mg-2.9Zn-0.7Zr as the matrix and 1wt% nano HA particles as reinforcement; it had a corrosion rate of 0.75 mm/year.152 A nano-sized β-tricalcium phosphate/Mg-3Zn-Ca composite was produced and showed a UTS of 125 MPa and elongation of 2.85%.153 Poly (L-lactic) acid-Mg65Zn30Ca5 composites were studied as potential orthopaedic implant candidates; they showed high corrosion resistance and good antibacterial properties.154 A collagen (10%)-hydroxyapatite (80%)-Mg (10%) composite scaffold was developed as a bone substitute and showed favourable bone healing and regeneration.155 A novel Mg nanocomposite scaffold was fabricated and demonstrated that a Mg cationic microenvironment promotes cell viability and osteogenic differentiation properties in vitro leading to effective bone defect repair.156, 157 ...
In vitro study of the PLLA-Mg65Zn30Ca5 composites as potential biodegradable materials for bone implants
1
2021
... Mg MMCs show a wide range of mechanical and corrosion behaviours because of the wide range of reinforcements and their content, distribution and size. The manufacturing methods are usually powder metallurgy or stir casting. The matrix materials are biomedical Mg alloys such as Mg-Ca, Mg-Al, Mg-Zn and Mg-RE. Calcium phosphate-based ceramics (like calcium polyphosphate, hydroxyapatite and tri-calcium phosphate), calcium, bioactive glass and zinc oxide have all been used to reinforce Mg MMCs. The amount, distribution and size of reinforcements are very important for the mechanical and bio-corrosion properties of Mg MMCs. For example, fluorapatite nanoparticles (up to 20%) have been used to improve the mechanical properties of AZ91/FA MMC.148 Mg/ZnO MMCs (20wt% ZnO nanoparticles) have been prepared using powder metallurgy and confer improved tensile strength, hardness and corrosion resistance but with reduced elongation.149 ZK60/CPP (calcium polyphosphate particles) MMCs have been produced with a compressive strength of 495 MPa.150 Gu et al.151 developed Mg-hydroxyapatite (10wt%, 20wt% and 30wt%) composites using powder metallurgy. Mg/10HA composites showed higher YS, lower UTS and elongation, reduced corrosion resistance and no toxicity. An MMC was fabricated using Mg-2.9Zn-0.7Zr as the matrix and 1wt% nano HA particles as reinforcement; it had a corrosion rate of 0.75 mm/year.152 A nano-sized β-tricalcium phosphate/Mg-3Zn-Ca composite was produced and showed a UTS of 125 MPa and elongation of 2.85%.153 Poly (L-lactic) acid-Mg65Zn30Ca5 composites were studied as potential orthopaedic implant candidates; they showed high corrosion resistance and good antibacterial properties.154 A collagen (10%)-hydroxyapatite (80%)-Mg (10%) composite scaffold was developed as a bone substitute and showed favourable bone healing and regeneration.155 A novel Mg nanocomposite scaffold was fabricated and demonstrated that a Mg cationic microenvironment promotes cell viability and osteogenic differentiation properties in vitro leading to effective bone defect repair.156, 157 ...
In vitro characterization of novel nanostructured collagen-hydroxyapatite composite scaffolds doped with magnesium with improved biodegradation rate for hard tissue regeneration
1
2021
... Mg MMCs show a wide range of mechanical and corrosion behaviours because of the wide range of reinforcements and their content, distribution and size. The manufacturing methods are usually powder metallurgy or stir casting. The matrix materials are biomedical Mg alloys such as Mg-Ca, Mg-Al, Mg-Zn and Mg-RE. Calcium phosphate-based ceramics (like calcium polyphosphate, hydroxyapatite and tri-calcium phosphate), calcium, bioactive glass and zinc oxide have all been used to reinforce Mg MMCs. The amount, distribution and size of reinforcements are very important for the mechanical and bio-corrosion properties of Mg MMCs. For example, fluorapatite nanoparticles (up to 20%) have been used to improve the mechanical properties of AZ91/FA MMC.148 Mg/ZnO MMCs (20wt% ZnO nanoparticles) have been prepared using powder metallurgy and confer improved tensile strength, hardness and corrosion resistance but with reduced elongation.149 ZK60/CPP (calcium polyphosphate particles) MMCs have been produced with a compressive strength of 495 MPa.150 Gu et al.151 developed Mg-hydroxyapatite (10wt%, 20wt% and 30wt%) composites using powder metallurgy. Mg/10HA composites showed higher YS, lower UTS and elongation, reduced corrosion resistance and no toxicity. An MMC was fabricated using Mg-2.9Zn-0.7Zr as the matrix and 1wt% nano HA particles as reinforcement; it had a corrosion rate of 0.75 mm/year.152 A nano-sized β-tricalcium phosphate/Mg-3Zn-Ca composite was produced and showed a UTS of 125 MPa and elongation of 2.85%.153 Poly (L-lactic) acid-Mg65Zn30Ca5 composites were studied as potential orthopaedic implant candidates; they showed high corrosion resistance and good antibacterial properties.154 A collagen (10%)-hydroxyapatite (80%)-Mg (10%) composite scaffold was developed as a bone substitute and showed favourable bone healing and regeneration.155 A novel Mg nanocomposite scaffold was fabricated and demonstrated that a Mg cationic microenvironment promotes cell viability and osteogenic differentiation properties in vitro leading to effective bone defect repair.156, 157 ...
Stepwise 3D-spatio-temporal magnesium cationic niche: Nanocomposite scaffold mediated microenvironment for modulating intramembranous ossification
1
2021
... Mg MMCs show a wide range of mechanical and corrosion behaviours because of the wide range of reinforcements and their content, distribution and size. The manufacturing methods are usually powder metallurgy or stir casting. The matrix materials are biomedical Mg alloys such as Mg-Ca, Mg-Al, Mg-Zn and Mg-RE. Calcium phosphate-based ceramics (like calcium polyphosphate, hydroxyapatite and tri-calcium phosphate), calcium, bioactive glass and zinc oxide have all been used to reinforce Mg MMCs. The amount, distribution and size of reinforcements are very important for the mechanical and bio-corrosion properties of Mg MMCs. For example, fluorapatite nanoparticles (up to 20%) have been used to improve the mechanical properties of AZ91/FA MMC.148 Mg/ZnO MMCs (20wt% ZnO nanoparticles) have been prepared using powder metallurgy and confer improved tensile strength, hardness and corrosion resistance but with reduced elongation.149 ZK60/CPP (calcium polyphosphate particles) MMCs have been produced with a compressive strength of 495 MPa.150 Gu et al.151 developed Mg-hydroxyapatite (10wt%, 20wt% and 30wt%) composites using powder metallurgy. Mg/10HA composites showed higher YS, lower UTS and elongation, reduced corrosion resistance and no toxicity. An MMC was fabricated using Mg-2.9Zn-0.7Zr as the matrix and 1wt% nano HA particles as reinforcement; it had a corrosion rate of 0.75 mm/year.152 A nano-sized β-tricalcium phosphate/Mg-3Zn-Ca composite was produced and showed a UTS of 125 MPa and elongation of 2.85%.153 Poly (L-lactic) acid-Mg65Zn30Ca5 composites were studied as potential orthopaedic implant candidates; they showed high corrosion resistance and good antibacterial properties.154 A collagen (10%)-hydroxyapatite (80%)-Mg (10%) composite scaffold was developed as a bone substitute and showed favourable bone healing and regeneration.155 A novel Mg nanocomposite scaffold was fabricated and demonstrated that a Mg cationic microenvironment promotes cell viability and osteogenic differentiation properties in vitro leading to effective bone defect repair.156, 157 ...
3D-printed nanocomposite scaffolds with tunable magnesium ionic microenvironment induce in situ bone tissue regeneration
1
2019
... Mg MMCs show a wide range of mechanical and corrosion behaviours because of the wide range of reinforcements and their content, distribution and size. The manufacturing methods are usually powder metallurgy or stir casting. The matrix materials are biomedical Mg alloys such as Mg-Ca, Mg-Al, Mg-Zn and Mg-RE. Calcium phosphate-based ceramics (like calcium polyphosphate, hydroxyapatite and tri-calcium phosphate), calcium, bioactive glass and zinc oxide have all been used to reinforce Mg MMCs. The amount, distribution and size of reinforcements are very important for the mechanical and bio-corrosion properties of Mg MMCs. For example, fluorapatite nanoparticles (up to 20%) have been used to improve the mechanical properties of AZ91/FA MMC.148 Mg/ZnO MMCs (20wt% ZnO nanoparticles) have been prepared using powder metallurgy and confer improved tensile strength, hardness and corrosion resistance but with reduced elongation.149 ZK60/CPP (calcium polyphosphate particles) MMCs have been produced with a compressive strength of 495 MPa.150 Gu et al.151 developed Mg-hydroxyapatite (10wt%, 20wt% and 30wt%) composites using powder metallurgy. Mg/10HA composites showed higher YS, lower UTS and elongation, reduced corrosion resistance and no toxicity. An MMC was fabricated using Mg-2.9Zn-0.7Zr as the matrix and 1wt% nano HA particles as reinforcement; it had a corrosion rate of 0.75 mm/year.152 A nano-sized β-tricalcium phosphate/Mg-3Zn-Ca composite was produced and showed a UTS of 125 MPa and elongation of 2.85%.153 Poly (L-lactic) acid-Mg65Zn30Ca5 composites were studied as potential orthopaedic implant candidates; they showed high corrosion resistance and good antibacterial properties.154 A collagen (10%)-hydroxyapatite (80%)-Mg (10%) composite scaffold was developed as a bone substitute and showed favourable bone healing and regeneration.155 A novel Mg nanocomposite scaffold was fabricated and demonstrated that a Mg cationic microenvironment promotes cell viability and osteogenic differentiation properties in vitro leading to effective bone defect repair.156, 157 ...
Topological design and additive manufacturing of porous metals for bone scaffolds and orthopaedic implants: A review
1
2016
... Porous implants (also called scaffolds) are under the spotlight for orthopaedic applications, because their interconnected pore structure encourages tissue ingrowth and survival of the vascular system required for continuing bone development.158, 159 Such interconnected pore networks facilitate the delivery of oxygen and nutrients to the cells and the removal of products stemming from cell metabolism and from degradation of the scaffold.160, 161 Moreover, the material’s modulus can be controlled via the porosity, which enables the design of implant materials with a modulus close to that of human bone.162 Other mechanical properties of Mg scaffolds can also be adjusted by changes to the porosity and pore size.163 Razavi et al.164 have specifically proposed that Mg-based alloys can be employed as biocompatible, bioactive, and biodegradable scaffolds for orthopaedic applications. ...
Bone ingrowth characteristics of porous tantalum and carbon fiber interbody devices: an experimental study in pigs
1
2004
... Porous implants (also called scaffolds) are under the spotlight for orthopaedic applications, because their interconnected pore structure encourages tissue ingrowth and survival of the vascular system required for continuing bone development.158, 159 Such interconnected pore networks facilitate the delivery of oxygen and nutrients to the cells and the removal of products stemming from cell metabolism and from degradation of the scaffold.160, 161 Moreover, the material’s modulus can be controlled via the porosity, which enables the design of implant materials with a modulus close to that of human bone.162 Other mechanical properties of Mg scaffolds can also be adjusted by changes to the porosity and pore size.163 Razavi et al.164 have specifically proposed that Mg-based alloys can be employed as biocompatible, bioactive, and biodegradable scaffolds for orthopaedic applications. ...
The influence of pore size on colonization of poly(L-lactide-glycolide) scaffolds with human osteoblast-like MG 63 cells in vitro
1
2008
... Porous implants (also called scaffolds) are under the spotlight for orthopaedic applications, because their interconnected pore structure encourages tissue ingrowth and survival of the vascular system required for continuing bone development.158, 159 Such interconnected pore networks facilitate the delivery of oxygen and nutrients to the cells and the removal of products stemming from cell metabolism and from degradation of the scaffold.160, 161 Moreover, the material’s modulus can be controlled via the porosity, which enables the design of implant materials with a modulus close to that of human bone.162 Other mechanical properties of Mg scaffolds can also be adjusted by changes to the porosity and pore size.163 Razavi et al.164 have specifically proposed that Mg-based alloys can be employed as biocompatible, bioactive, and biodegradable scaffolds for orthopaedic applications. ...
Resorbable polymeric scaffolds for bone tissue engineering: the influence of their microstructure on the growth of human osteoblast-like MG 63 cells
1
2009
... Porous implants (also called scaffolds) are under the spotlight for orthopaedic applications, because their interconnected pore structure encourages tissue ingrowth and survival of the vascular system required for continuing bone development.158, 159 Such interconnected pore networks facilitate the delivery of oxygen and nutrients to the cells and the removal of products stemming from cell metabolism and from degradation of the scaffold.160, 161 Moreover, the material’s modulus can be controlled via the porosity, which enables the design of implant materials with a modulus close to that of human bone.162 Other mechanical properties of Mg scaffolds can also be adjusted by changes to the porosity and pore size.163 Razavi et al.164 have specifically proposed that Mg-based alloys can be employed as biocompatible, bioactive, and biodegradable scaffolds for orthopaedic applications. ...
Porous metals and metallic foams: current status and recent developments
1
2008
... Porous implants (also called scaffolds) are under the spotlight for orthopaedic applications, because their interconnected pore structure encourages tissue ingrowth and survival of the vascular system required for continuing bone development.158, 159 Such interconnected pore networks facilitate the delivery of oxygen and nutrients to the cells and the removal of products stemming from cell metabolism and from degradation of the scaffold.160, 161 Moreover, the material’s modulus can be controlled via the porosity, which enables the design of implant materials with a modulus close to that of human bone.162 Other mechanical properties of Mg scaffolds can also be adjusted by changes to the porosity and pore size.163 Razavi et al.164 have specifically proposed that Mg-based alloys can be employed as biocompatible, bioactive, and biodegradable scaffolds for orthopaedic applications. ...
A novel open-porous magnesium scaffold with controllable microstructures and properties for bone regeneration
1
2016
... Porous implants (also called scaffolds) are under the spotlight for orthopaedic applications, because their interconnected pore structure encourages tissue ingrowth and survival of the vascular system required for continuing bone development.158, 159 Such interconnected pore networks facilitate the delivery of oxygen and nutrients to the cells and the removal of products stemming from cell metabolism and from degradation of the scaffold.160, 161 Moreover, the material’s modulus can be controlled via the porosity, which enables the design of implant materials with a modulus close to that of human bone.162 Other mechanical properties of Mg scaffolds can also be adjusted by changes to the porosity and pore size.163 Razavi et al.164 have specifically proposed that Mg-based alloys can be employed as biocompatible, bioactive, and biodegradable scaffolds for orthopaedic applications. ...
In vitro study of nanostructured diopside coating on Mg alloy orthopedic implants
1
2014
... Porous implants (also called scaffolds) are under the spotlight for orthopaedic applications, because their interconnected pore structure encourages tissue ingrowth and survival of the vascular system required for continuing bone development.158, 159 Such interconnected pore networks facilitate the delivery of oxygen and nutrients to the cells and the removal of products stemming from cell metabolism and from degradation of the scaffold.160, 161 Moreover, the material’s modulus can be controlled via the porosity, which enables the design of implant materials with a modulus close to that of human bone.162 Other mechanical properties of Mg scaffolds can also be adjusted by changes to the porosity and pore size.163 Razavi et al.164 have specifically proposed that Mg-based alloys can be employed as biocompatible, bioactive, and biodegradable scaffolds for orthopaedic applications. ...
Additively manufactured biodegradable porous magnesium
3
2018
... Powder metallurgy, laser additive manufacturing, the metal/gas eutectic unidirectional solidification process and the negative salt-pattern moulding method have all been used to produce a porous Mg scaffold. Porous WE43 scaffolds were fabricated by laser-powder bed fusion and their in vitro performance was first reported by Li et al.165 The diamond lattice was adopted to construct a porous scaffold cylinder with a diameter of 10 mm and a height of 11.2 mm, as shown in Figure 6A. Geng et al.166 reported that the pore size and porosity (48%) of a honeycomb-structured Mg scaffold (shown in Figure 6B167) can be controlled by the laser perforation technique. Witte et al. reported an open porous AZ91 alloy scaffold with porosity ranging from 72% to 76% and a pore size varying between 10 and 1000 µm, which was created by infiltrating molten Mg into a NaCl preform and then washing out the salt preform in NaOH solution.40, 168 Gu et al.169 produced a lotus-type porous pure Mg using a metal/gas eutectic unidirectional solidification method, which showed a slower decay in compressive YS than that of pure Mg during immersion in simulated body fluid. ...
... Currently, some Mg alloys such as WE43,165, 223 AZ91,224 Mg-9wt% Al225 and ZK60226-228 are fabricated using laser additive manufacturing. The in vitro static degradation behaviour has been studied.165, 226, 229, 230 However, the in vivo response, especially the dynamic biodegradation including geometric and mechanical changes, have been barely reported. The dynamic degradation of Mg leads to varied biological interactions and mechanical performance. Therefore, the dynamic evolution of Mg implants in the physiological environment needs to be investigated, including changes in the implant shape, variations in the mechanical strength and elastic modulus, pH variation, the release of corrosion products, the amount of released metallic ions, hydrogen gas and the changed biocompatibility. In addition, the related modelling, which can accurately simulate the dynamic physiological-chemical-mechanical variation during the biodegradation process along with bone healing, needs development. ...
... 165, 226, 229, 230 However, the in vivo response, especially the dynamic biodegradation including geometric and mechanical changes, have been barely reported. The dynamic degradation of Mg leads to varied biological interactions and mechanical performance. Therefore, the dynamic evolution of Mg implants in the physiological environment needs to be investigated, including changes in the implant shape, variations in the mechanical strength and elastic modulus, pH variation, the release of corrosion products, the amount of released metallic ions, hydrogen gas and the changed biocompatibility. In addition, the related modelling, which can accurately simulate the dynamic physiological-chemical-mechanical variation during the biodegradation process along with bone healing, needs development. ...
Study on β-TCP coated porous Mg as a bone tissue engineering scaffold material
1
2009
... Powder metallurgy, laser additive manufacturing, the metal/gas eutectic unidirectional solidification process and the negative salt-pattern moulding method have all been used to produce a porous Mg scaffold. Porous WE43 scaffolds were fabricated by laser-powder bed fusion and their in vitro performance was first reported by Li et al.165 The diamond lattice was adopted to construct a porous scaffold cylinder with a diameter of 10 mm and a height of 11.2 mm, as shown in Figure 6A. Geng et al.166 reported that the pore size and porosity (48%) of a honeycomb-structured Mg scaffold (shown in Figure 6B167) can be controlled by the laser perforation technique. Witte et al. reported an open porous AZ91 alloy scaffold with porosity ranging from 72% to 76% and a pore size varying between 10 and 1000 µm, which was created by infiltrating molten Mg into a NaCl preform and then washing out the salt preform in NaOH solution.40, 168 Gu et al.169 produced a lotus-type porous pure Mg using a metal/gas eutectic unidirectional solidification method, which showed a slower decay in compressive YS than that of pure Mg during immersion in simulated body fluid. ...
Study on compression behavior of porous magnesium used as bone tissue engineering scaffolds
2
2009
... Powder metallurgy, laser additive manufacturing, the metal/gas eutectic unidirectional solidification process and the negative salt-pattern moulding method have all been used to produce a porous Mg scaffold. Porous WE43 scaffolds were fabricated by laser-powder bed fusion and their in vitro performance was first reported by Li et al.165 The diamond lattice was adopted to construct a porous scaffold cylinder with a diameter of 10 mm and a height of 11.2 mm, as shown in Figure 6A. Geng et al.166 reported that the pore size and porosity (48%) of a honeycomb-structured Mg scaffold (shown in Figure 6B167) can be controlled by the laser perforation technique. Witte et al. reported an open porous AZ91 alloy scaffold with porosity ranging from 72% to 76% and a pore size varying between 10 and 1000 µm, which was created by infiltrating molten Mg into a NaCl preform and then washing out the salt preform in NaOH solution.40, 168 Gu et al.169 produced a lotus-type porous pure Mg using a metal/gas eutectic unidirectional solidification method, which showed a slower decay in compressive YS than that of pure Mg during immersion in simulated body fluid. ...
...
167 Copyright IOP Publishing. Reproduced with permission. All rights reserved. Scale bars: 1 mm.
It has been stated that the scaffold structure provides three-dimensional space for cell adhesion and ingrowth, giving good biocompatibility.170 More importantly, the laser additive manufacturing technology used to build the scaffold has significant advantages in the fabrication of complex porous structures and customised implants addressing specific clinical needs. However, the pore structure (including pore size, shape, connectivity, etc.) needs to be carefully controlled, because this is one of the key factors determining the mechanical properties of porous Mg. ...
Biodegradable magnesium scaffolds: Part II: peri-implant bone remodeling
1
2007
... Powder metallurgy, laser additive manufacturing, the metal/gas eutectic unidirectional solidification process and the negative salt-pattern moulding method have all been used to produce a porous Mg scaffold. Porous WE43 scaffolds were fabricated by laser-powder bed fusion and their in vitro performance was first reported by Li et al.165 The diamond lattice was adopted to construct a porous scaffold cylinder with a diameter of 10 mm and a height of 11.2 mm, as shown in Figure 6A. Geng et al.166 reported that the pore size and porosity (48%) of a honeycomb-structured Mg scaffold (shown in Figure 6B167) can be controlled by the laser perforation technique. Witte et al. reported an open porous AZ91 alloy scaffold with porosity ranging from 72% to 76% and a pore size varying between 10 and 1000 µm, which was created by infiltrating molten Mg into a NaCl preform and then washing out the salt preform in NaOH solution.40, 168 Gu et al.169 produced a lotus-type porous pure Mg using a metal/gas eutectic unidirectional solidification method, which showed a slower decay in compressive YS than that of pure Mg during immersion in simulated body fluid. ...
Degradation and cytotoxicity of lotus-type porous pure magnesium as potential tissue engineering scaffold material
1
2010
... Powder metallurgy, laser additive manufacturing, the metal/gas eutectic unidirectional solidification process and the negative salt-pattern moulding method have all been used to produce a porous Mg scaffold. Porous WE43 scaffolds were fabricated by laser-powder bed fusion and their in vitro performance was first reported by Li et al.165 The diamond lattice was adopted to construct a porous scaffold cylinder with a diameter of 10 mm and a height of 11.2 mm, as shown in Figure 6A. Geng et al.166 reported that the pore size and porosity (48%) of a honeycomb-structured Mg scaffold (shown in Figure 6B167) can be controlled by the laser perforation technique. Witte et al. reported an open porous AZ91 alloy scaffold with porosity ranging from 72% to 76% and a pore size varying between 10 and 1000 µm, which was created by infiltrating molten Mg into a NaCl preform and then washing out the salt preform in NaOH solution.40, 168 Gu et al.169 produced a lotus-type porous pure Mg using a metal/gas eutectic unidirectional solidification method, which showed a slower decay in compressive YS than that of pure Mg during immersion in simulated body fluid. ...
Fabrication techniques of biomimetic scaffolds in three-dimensional cell culture: A review
1
2021
... It has been stated that the scaffold structure provides three-dimensional space for cell adhesion and ingrowth, giving good biocompatibility.170 More importantly, the laser additive manufacturing technology used to build the scaffold has significant advantages in the fabrication of complex porous structures and customised implants addressing specific clinical needs. However, the pore structure (including pore size, shape, connectivity, etc.) needs to be carefully controlled, because this is one of the key factors determining the mechanical properties of porous Mg. ...
Current status on clinical applications of magnesium-based orthopaedic implants: A review from clinical translational perspective
1
2017
... Besides the traditional techniques such as melting and casting, other fabrication methods have been developed to obtain biomedical Mg implants, including powder metallurgy, metallic glass forming and laser additive manufacturing. The different fabrication processes directly affect the microstructure and relevant biological performance, mechanical properties and bio-corrosion behaviour.118, 171 In particular, the accurate regulation of alloying elements, microstructure design, biocompatibility tailoring, machinability and precise control of porous structure need to be considered and further investigated. Moreover, the in vitro and in vivo testing needs to be carefully studied. ...
1
2015
... A tensile test machine with tensile grips and extensometer can be obtained to measure the characteristics of alloys. Tensile tests are simple, inexpensive and standardised and measure the YS, UTS and elongation. Results from tensile testing can be used for material comparison, quality control and alloy development. Standard tensile tests can follow ASTM B557172 and ISO 6892-1.173 In clinical applications the Mg implant is continuously under the load in a physiological environment. Fatigue-corrosion testing is also necessary because of the specific requirements of orthopaedic applications. Here the ASTM testing standard WK61103174 can be employed. ...
1
2019
... A tensile test machine with tensile grips and extensometer can be obtained to measure the characteristics of alloys. Tensile tests are simple, inexpensive and standardised and measure the YS, UTS and elongation. Results from tensile testing can be used for material comparison, quality control and alloy development. Standard tensile tests can follow ASTM B557172 and ISO 6892-1.173 In clinical applications the Mg implant is continuously under the load in a physiological environment. Fatigue-corrosion testing is also necessary because of the specific requirements of orthopaedic applications. Here the ASTM testing standard WK61103174 can be employed. ...
1
2017
... A tensile test machine with tensile grips and extensometer can be obtained to measure the characteristics of alloys. Tensile tests are simple, inexpensive and standardised and measure the YS, UTS and elongation. Results from tensile testing can be used for material comparison, quality control and alloy development. Standard tensile tests can follow ASTM B557172 and ISO 6892-1.173 In clinical applications the Mg implant is continuously under the load in a physiological environment. Fatigue-corrosion testing is also necessary because of the specific requirements of orthopaedic applications. Here the ASTM testing standard WK61103174 can be employed. ...
Using a synthetic body fluid (SBF) solution of 27 mM HCO3 - to make bone substitutes more osteointegrative
1
2008
... In vitro experiments are convenient and can provide quick and reasonable feedback on efficacy as compared with in vivo testing. The simulated body fluid method is popular; it is an aqueous solution with ion concentrations and pH value equal to those of human body fluids. The corrosion of Mg in simulated body fluid increases the pH because of alkalisation, which affects the biodegradation rate. In order to minimise the pH variation of simulated body fluid, the solution needs to be refreshed every 24 hours and the ratio of sample surface to the volume of solution kept high. Table 6 shows several solutions used in in vitro tests.175 ...
Microstructure, mechanical properties, biocorrosion behavior, and cytotoxicity of as-extruded Mg-Nd-Zn-Zr alloy with different extrusion ratios
1
2012
... The tested Mg specimen is placed in the corrosion medium for a period of time, at the end of which the Mg alloy is taken out and washed with a cleaning solution (such as dilute chromic acid) to remove all corrosion products and then the resultant mass change is measured. This classic method has been used by a number of researchers.117, 176-181 ...
The Effect of pre-processing and grain structure on the bio-corrosion and fatigue resistance of magnesium alloy AZ31
2007
Biodegradable magnesium-hydroxyapatite metal matrix composites
1
2007
... 2) A hydrogen evolution method has been developed by Song et al.182 based on the collection of hydrogen gas during degradation of Mg in aqueous solutions. The hydrogen evolution measurement is currently very popular and is widely accepted by many researchers.10, 42, 59, 106, 107, 178-181 The mechanism of this measurement is simple and easy to understand, and is based on the reaction below: ...
Improve corrosion resistance of magnesium in simulated body fluid by dicalcium phosphate dihydrate coating
2009
A survey of bio-corrosion rates of magnesium alloys
2010
Magnesium alloys as implant materials principles of property design for Mg-RE alloys
2
2010
... The tested Mg specimen is placed in the corrosion medium for a period of time, at the end of which the Mg alloy is taken out and washed with a cleaning solution (such as dilute chromic acid) to remove all corrosion products and then the resultant mass change is measured. This classic method has been used by a number of researchers.117, 176-181 ...
... 2) A hydrogen evolution method has been developed by Song et al.182 based on the collection of hydrogen gas during degradation of Mg in aqueous solutions. The hydrogen evolution measurement is currently very popular and is widely accepted by many researchers.10, 42, 59, 106, 107, 178-181 The mechanism of this measurement is simple and easy to understand, and is based on the reaction below: ...
Magnesium technology
1
2001
... 2) A hydrogen evolution method has been developed by Song et al.182 based on the collection of hydrogen gas during degradation of Mg in aqueous solutions. The hydrogen evolution measurement is currently very popular and is widely accepted by many researchers.10, 42, 59, 106, 107, 178-181 The mechanism of this measurement is simple and easy to understand, and is based on the reaction below: ...
Corrosion behaviour of AZ31 magnesium alloy with different grain sizes in simulated biological fluids
1
2010
... 3) Electrochemical measurement is widely used to measure the in vitro degradation behaviour of Mg alloys. The greatest advantage is that it can be used to obtain the real-time corrosion rate.106, 148, 183-185 Changes in corrosion behaviour can be instantaneously observed. Generally, the Mg sample is used as the working electrode, platinum as the counter electrode and a saturated calomel electrode as the reference electrode. Using this method, more corrosion information can be accessed, such as the relative rates of the anodic and cathodic reactions over a range of potentials.186 A number of investigations indicate that the corrosion rate of Mg alloys measured by electrochemical testing agrees with that by hydrogen evolution and helps to increase the understanding of how corrosion takes place.119, 186, 187 ...
Effect of Y on the bio-corrosion behavior of extruded Mg-Zn-Mn alloy in Hank’s solution
2010
Influence of microstructure on the in-vitro degradation behaviour of magnesium alloys
1
2010
... 3) Electrochemical measurement is widely used to measure the in vitro degradation behaviour of Mg alloys. The greatest advantage is that it can be used to obtain the real-time corrosion rate.106, 148, 183-185 Changes in corrosion behaviour can be instantaneously observed. Generally, the Mg sample is used as the working electrode, platinum as the counter electrode and a saturated calomel electrode as the reference electrode. Using this method, more corrosion information can be accessed, such as the relative rates of the anodic and cathodic reactions over a range of potentials.186 A number of investigations indicate that the corrosion rate of Mg alloys measured by electrochemical testing agrees with that by hydrogen evolution and helps to increase the understanding of how corrosion takes place.119, 186, 187 ...
Assessing the corrosion of biodegradable magnesium implants: a critical review of current methodologies and their limitations
4
2012
... 3) Electrochemical measurement is widely used to measure the in vitro degradation behaviour of Mg alloys. The greatest advantage is that it can be used to obtain the real-time corrosion rate.106, 148, 183-185 Changes in corrosion behaviour can be instantaneously observed. Generally, the Mg sample is used as the working electrode, platinum as the counter electrode and a saturated calomel electrode as the reference electrode. Using this method, more corrosion information can be accessed, such as the relative rates of the anodic and cathodic reactions over a range of potentials.186 A number of investigations indicate that the corrosion rate of Mg alloys measured by electrochemical testing agrees with that by hydrogen evolution and helps to increase the understanding of how corrosion takes place.119, 186, 187 ...
... , 186, 187 ...
... The degradation rate of Mg alloys determines the ion release rate in the physiological environment. The amount of released elements significantly affects the biocompatibility of the Mg alloys. An evaluation of the biosafety of Mg implants must be performed. Currently, preparation of the extracts from medical devices for cytotoxicity testing needs to follow Parts 5 and 12 of ISO 10993.198, 209 However, Mg alloys can react with an aqueous environment, release Mg ions and produce a higher pH value and osmolality in the surrounding medium,186 which is significantly affected by the constituents of the medium.210 In order to mimic an in vivo environment, a cell culture medium supplemented with serum is recommended.211 Wang et al.212 proposed a modified cytotoxicity testing standard for biodegradable Mg-based materials: a minimum 6-fold to a maximum 10-fold dilution of extracts from Mg implants for cytotoxicity tests. It has been reported that the test conditions can significantly influence the cytotoxicity testing of biodegradable metallic materials, which further suggested that the test conditions need to be carefully specified and different studies need to be cautiously compared.213 ...
... Mg is an essential ion in metabolism and can encourage bone growth, which helps the proper fixation of an implant into the host bone and potentially allows full healing of bone defects after degradation.186, 214 Importantly, biomaterials need to be designed to be bioactive and/or bioresorbable to improve tissue growth. Therefore, a biodegradable Mg alloy with great biocompatibility can make an ideal implant for load-bearing orthopaedic applications. Complex and/or customised shapes consistent with specific patient needs are required in real clinics nowadays. Thus, additive manufacturing is assuming greater and greater importance for implant manufacture, including for Mg. In addition, the influence of local pH changes on the adjacent tissue, evolution of hydrogen gas and the concentration of released metallic ions caused by bulk Mg-based implants can be reduced by adopting Mg scaffolds due to the smaller volume of implant. Furthermore, a material with porosity changing across the volume (a functionally-graded material) is currently believed to improve osseo-integration.215 This can be achieved by an additively-manufactureld scaffold. These unique features suggest that additively-manufactureld Mg scaffolds with bone-mimicking characteristics will become promising orthopaedic implants, possessing sufficient mechanical strength and ductility, low elastic modulus, excellent biocompatibility, and a complex shape. ...
Corrosion behaviour of AZ21, AZ501 and AZ91 in sodium chloride
1
1998
... 3) Electrochemical measurement is widely used to measure the in vitro degradation behaviour of Mg alloys. The greatest advantage is that it can be used to obtain the real-time corrosion rate.106, 148, 183-185 Changes in corrosion behaviour can be instantaneously observed. Generally, the Mg sample is used as the working electrode, platinum as the counter electrode and a saturated calomel electrode as the reference electrode. Using this method, more corrosion information can be accessed, such as the relative rates of the anodic and cathodic reactions over a range of potentials.186 A number of investigations indicate that the corrosion rate of Mg alloys measured by electrochemical testing agrees with that by hydrogen evolution and helps to increase the understanding of how corrosion takes place.119, 186, 187 ...
Engineered bio-nanocomposite magnesium scaffold for bone tissue regeneration
1
2019
... 4) Micro-computed tomography (a non-destructive technique) has been demonstrated to be a powerful technique to monitor in vitro degradation.105, 188-190 The evaluation of the bio-corrosion rate depends on a comprehensive observation of the Mg specimen before and after immersion testing. The volume losses of the samples can be calculated and then converted to the same units (mm/year). Lu et al.105 reported the corrosion morphology and degradation rate of Mg-3Zn-0.3Ca alloys using three-dimensional reconstructions, as shown in Figure 7. The as-cast Mg-3Zn-0.3Ca has been severely attacked by corrosion and has lost 34.3% of its initial volume. ...
Mechanical and in vitro degradation behavior of magnesium-bioactive glass composites prepared by SPS for biomedical applications
2019
In vitro and in vivo degradation behavior of Mg-2Sr-Ca and Mg-2Sr-Zn alloys
1
2020
... 4) Micro-computed tomography (a non-destructive technique) has been demonstrated to be a powerful technique to monitor in vitro degradation.105, 188-190 The evaluation of the bio-corrosion rate depends on a comprehensive observation of the Mg specimen before and after immersion testing. The volume losses of the samples can be calculated and then converted to the same units (mm/year). Lu et al.105 reported the corrosion morphology and degradation rate of Mg-3Zn-0.3Ca alloys using three-dimensional reconstructions, as shown in Figure 7. The as-cast Mg-3Zn-0.3Ca has been severely attacked by corrosion and has lost 34.3% of its initial volume. ...
Biocorrosion of magnesium alloys: a new principle in cardiovascular implant technology?
1
2003
... The in vivo assessment of the compatibility of biomaterials and medical devices with tissue is important for the development and implementation of implants for human use. Many in vivo studies have been conducted to understand the degradation process and the associated mechanisms. Animal models are adopted in order to determine the response to the biomaterials or medical devices, such as the interactions of various cell types with the implants, endocrine factors acting on cells around the implant and interactions with blood-borne cells and proteins. In vivo studies have mainly been performed on small animals, such as guinea pigs, rats and rabbits. Heublein et al.191 investigated a cardiovascular stent (AE21 alloy) in domestic pigs. There is a report describing the implantation of Mg chips into the spines of sheep.192 The first comprehensive in vivo study on Mg alloys was carried out by Witte et al.39 on four different Mg alloys (AZ31, AZ91, WE43 and LAE442), and these four Mg alloys were implanted into the femurs of guinea pigs. A newly-formed mineral phase was observed on the surface of the Mg implants during implant degradation, which stained with calcein green under fluorescent light (Figure 8A).39 The in vivo bio-corrosion morphology of the remaining Mg alloy in the guinea pig femora is shown in Figures 8B and C.109 It can be seen that the AZ91D rod was almost completely corroded, while the LAE442 rod was corroded more uniformly. Both of these Mg alloys exhibited good biocompatibility as evidenced by the direct contact with newly-formed bone. ...
The effects of magnesium particles in posterolateral spinal fusion: an experimental in vivo study in a sheep model
1
2007
... The in vivo assessment of the compatibility of biomaterials and medical devices with tissue is important for the development and implementation of implants for human use. Many in vivo studies have been conducted to understand the degradation process and the associated mechanisms. Animal models are adopted in order to determine the response to the biomaterials or medical devices, such as the interactions of various cell types with the implants, endocrine factors acting on cells around the implant and interactions with blood-borne cells and proteins. In vivo studies have mainly been performed on small animals, such as guinea pigs, rats and rabbits. Heublein et al.191 investigated a cardiovascular stent (AE21 alloy) in domestic pigs. There is a report describing the implantation of Mg chips into the spines of sheep.192 The first comprehensive in vivo study on Mg alloys was carried out by Witte et al.39 on four different Mg alloys (AZ31, AZ91, WE43 and LAE442), and these four Mg alloys were implanted into the femurs of guinea pigs. A newly-formed mineral phase was observed on the surface of the Mg implants during implant degradation, which stained with calcein green under fluorescent light (Figure 8A).39 The in vivo bio-corrosion morphology of the remaining Mg alloy in the guinea pig femora is shown in Figures 8B and C.109 It can be seen that the AZ91D rod was almost completely corroded, while the LAE442 rod was corroded more uniformly. Both of these Mg alloys exhibited good biocompatibility as evidenced by the direct contact with newly-formed bone. ...
High-purity weight-bearing magnesium screw: Translational application in the healing of femoral neck fracture
1
2020
... Recently, some in vivo studies were carried out on large animal models. A goat was used to study the clinical capability of osteosynthesis of a lean Mg alloy (Mg-0.45Zn-0.45Ca) screw.51 In vivo transformation experiments on high-purity weight-bearing Mg screws were also carried out on goats.193 Small animals (rats) and large animals (sheep) have been used to compare the biodegradation rate, bone formation and in-growth of bone into Mg-0.45Zn-0.45Ca implants.194 A pig model was designed to evaluate the in vivo performance of a Mg-4Zn-0.1Sr anastomosis ring.195 A miniature pig has been employed to perform pre-clinical testing of human-sized Mg implants at multiple implantation sites.196 ...
Comparison of a resorbable magnesium implant in small and large growing-animal models
1
2018
... Recently, some in vivo studies were carried out on large animal models. A goat was used to study the clinical capability of osteosynthesis of a lean Mg alloy (Mg-0.45Zn-0.45Ca) screw.51 In vivo transformation experiments on high-purity weight-bearing Mg screws were also carried out on goats.193 Small animals (rats) and large animals (sheep) have been used to compare the biodegradation rate, bone formation and in-growth of bone into Mg-0.45Zn-0.45Ca implants.194 A pig model was designed to evaluate the in vivo performance of a Mg-4Zn-0.1Sr anastomosis ring.195 A miniature pig has been employed to perform pre-clinical testing of human-sized Mg implants at multiple implantation sites.196 ...
The design, development, and in vivo performance of intestinal anastomosis ring fabricated by magnesium-zinc-strontium alloy
1
2020
... Recently, some in vivo studies were carried out on large animal models. A goat was used to study the clinical capability of osteosynthesis of a lean Mg alloy (Mg-0.45Zn-0.45Ca) screw.51 In vivo transformation experiments on high-purity weight-bearing Mg screws were also carried out on goats.193 Small animals (rats) and large animals (sheep) have been used to compare the biodegradation rate, bone formation and in-growth of bone into Mg-0.45Zn-0.45Ca implants.194 A pig model was designed to evaluate the in vivo performance of a Mg-4Zn-0.1Sr anastomosis ring.195 A miniature pig has been employed to perform pre-clinical testing of human-sized Mg implants at multiple implantation sites.196 ...
Pre-clinical testing of human size magnesium implants in miniature pigs: Implant degradation and bone fracture healing at multiple implantation sites
1
2020
... Recently, some in vivo studies were carried out on large animal models. A goat was used to study the clinical capability of osteosynthesis of a lean Mg alloy (Mg-0.45Zn-0.45Ca) screw.51 In vivo transformation experiments on high-purity weight-bearing Mg screws were also carried out on goats.193 Small animals (rats) and large animals (sheep) have been used to compare the biodegradation rate, bone formation and in-growth of bone into Mg-0.45Zn-0.45Ca implants.194 A pig model was designed to evaluate the in vivo performance of a Mg-4Zn-0.1Sr anastomosis ring.195 A miniature pig has been employed to perform pre-clinical testing of human-sized Mg implants at multiple implantation sites.196 ...
Study of the in vitro cytotoxicity testing of medical devices
1
2015
... Cytotoxicity testing is one of the biological evaluation and screening tests that uses tissue cells in vitro to observe the effects of medical implants on cell growth, reproduction and morphology.197 It is an important indicator for quickly evaluating the biocompatibility of implants because it is fast, simple and highly sensitive. Three types of cytotoxicity test are specified in ISO 10993:198 extract, direct contact and indirect contact tests. The extract test is suitable for evaluating the toxicity of soluble substances released from implants. The direct contact test is the most sensitive and can be used to measure even weak cytotoxicity.199 The indirect contact test is used on implants with high toxicity and/or small molecular weight.200, 201 Bone marrow-derived mesenchymal stromal cells, murine fibroblast cells (L-929) and murine calvarial preosteoblasts (MC3T3-E1) are commonly used for cytotoxicity studies.202-207 The cytotoxicity assay includes cell adhesion, cell viability and proliferation assessments. Cell morphology can be viewed by fluorescence staining under an inverted fluorescence microscope. In order to investigate cell adhesion, samples seeded with MC3T3-E1 pre-osteoblasts were rinsed with phosphate-buffered saline (PBS).207 MC3T3-E1 cells were directly seeded onto Mg alloy to study the cell proliferation behaviour.208 A standard MTT assay was adopted to measure cell viability.202 ...
ISO 10993-5: biological evaluation of medical devices: tests for in vitro cytotoxicity
2
... Cytotoxicity testing is one of the biological evaluation and screening tests that uses tissue cells in vitro to observe the effects of medical implants on cell growth, reproduction and morphology.197 It is an important indicator for quickly evaluating the biocompatibility of implants because it is fast, simple and highly sensitive. Three types of cytotoxicity test are specified in ISO 10993:198 extract, direct contact and indirect contact tests. The extract test is suitable for evaluating the toxicity of soluble substances released from implants. The direct contact test is the most sensitive and can be used to measure even weak cytotoxicity.199 The indirect contact test is used on implants with high toxicity and/or small molecular weight.200, 201 Bone marrow-derived mesenchymal stromal cells, murine fibroblast cells (L-929) and murine calvarial preosteoblasts (MC3T3-E1) are commonly used for cytotoxicity studies.202-207 The cytotoxicity assay includes cell adhesion, cell viability and proliferation assessments. Cell morphology can be viewed by fluorescence staining under an inverted fluorescence microscope. In order to investigate cell adhesion, samples seeded with MC3T3-E1 pre-osteoblasts were rinsed with phosphate-buffered saline (PBS).207 MC3T3-E1 cells were directly seeded onto Mg alloy to study the cell proliferation behaviour.208 A standard MTT assay was adopted to measure cell viability.202 ...
... The degradation rate of Mg alloys determines the ion release rate in the physiological environment. The amount of released elements significantly affects the biocompatibility of the Mg alloys. An evaluation of the biosafety of Mg implants must be performed. Currently, preparation of the extracts from medical devices for cytotoxicity testing needs to follow Parts 5 and 12 of ISO 10993.198, 209 However, Mg alloys can react with an aqueous environment, release Mg ions and produce a higher pH value and osmolality in the surrounding medium,186 which is significantly affected by the constituents of the medium.210 In order to mimic an in vivo environment, a cell culture medium supplemented with serum is recommended.211 Wang et al.212 proposed a modified cytotoxicity testing standard for biodegradable Mg-based materials: a minimum 6-fold to a maximum 10-fold dilution of extracts from Mg implants for cytotoxicity tests. It has been reported that the test conditions can significantly influence the cytotoxicity testing of biodegradable metallic materials, which further suggested that the test conditions need to be carefully specified and different studies need to be cautiously compared.213 ...
Cytotoxicity testing of methyl and ethyl 2-cyanoacrylate using direct contact assay on osteoblast cell cultures
1
2013
... Cytotoxicity testing is one of the biological evaluation and screening tests that uses tissue cells in vitro to observe the effects of medical implants on cell growth, reproduction and morphology.197 It is an important indicator for quickly evaluating the biocompatibility of implants because it is fast, simple and highly sensitive. Three types of cytotoxicity test are specified in ISO 10993:198 extract, direct contact and indirect contact tests. The extract test is suitable for evaluating the toxicity of soluble substances released from implants. The direct contact test is the most sensitive and can be used to measure even weak cytotoxicity.199 The indirect contact test is used on implants with high toxicity and/or small molecular weight.200, 201 Bone marrow-derived mesenchymal stromal cells, murine fibroblast cells (L-929) and murine calvarial preosteoblasts (MC3T3-E1) are commonly used for cytotoxicity studies.202-207 The cytotoxicity assay includes cell adhesion, cell viability and proliferation assessments. Cell morphology can be viewed by fluorescence staining under an inverted fluorescence microscope. In order to investigate cell adhesion, samples seeded with MC3T3-E1 pre-osteoblasts were rinsed with phosphate-buffered saline (PBS).207 MC3T3-E1 cells were directly seeded onto Mg alloy to study the cell proliferation behaviour.208 A standard MTT assay was adopted to measure cell viability.202 ...
Cytotoxicity of dental alloys, metals, and ceramics assessed by millipore filter, agar overlay, and MTT tests
1
2000
... Cytotoxicity testing is one of the biological evaluation and screening tests that uses tissue cells in vitro to observe the effects of medical implants on cell growth, reproduction and morphology.197 It is an important indicator for quickly evaluating the biocompatibility of implants because it is fast, simple and highly sensitive. Three types of cytotoxicity test are specified in ISO 10993:198 extract, direct contact and indirect contact tests. The extract test is suitable for evaluating the toxicity of soluble substances released from implants. The direct contact test is the most sensitive and can be used to measure even weak cytotoxicity.199 The indirect contact test is used on implants with high toxicity and/or small molecular weight.200, 201 Bone marrow-derived mesenchymal stromal cells, murine fibroblast cells (L-929) and murine calvarial preosteoblasts (MC3T3-E1) are commonly used for cytotoxicity studies.202-207 The cytotoxicity assay includes cell adhesion, cell viability and proliferation assessments. Cell morphology can be viewed by fluorescence staining under an inverted fluorescence microscope. In order to investigate cell adhesion, samples seeded with MC3T3-E1 pre-osteoblasts were rinsed with phosphate-buffered saline (PBS).207 MC3T3-E1 cells were directly seeded onto Mg alloy to study the cell proliferation behaviour.208 A standard MTT assay was adopted to measure cell viability.202 ...
Cytotoxicity of titanium dioxide nanoparticles in mouse fibroblast cells
1
2008
... Cytotoxicity testing is one of the biological evaluation and screening tests that uses tissue cells in vitro to observe the effects of medical implants on cell growth, reproduction and morphology.197 It is an important indicator for quickly evaluating the biocompatibility of implants because it is fast, simple and highly sensitive. Three types of cytotoxicity test are specified in ISO 10993:198 extract, direct contact and indirect contact tests. The extract test is suitable for evaluating the toxicity of soluble substances released from implants. The direct contact test is the most sensitive and can be used to measure even weak cytotoxicity.199 The indirect contact test is used on implants with high toxicity and/or small molecular weight.200, 201 Bone marrow-derived mesenchymal stromal cells, murine fibroblast cells (L-929) and murine calvarial preosteoblasts (MC3T3-E1) are commonly used for cytotoxicity studies.202-207 The cytotoxicity assay includes cell adhesion, cell viability and proliferation assessments. Cell morphology can be viewed by fluorescence staining under an inverted fluorescence microscope. In order to investigate cell adhesion, samples seeded with MC3T3-E1 pre-osteoblasts were rinsed with phosphate-buffered saline (PBS).207 MC3T3-E1 cells were directly seeded onto Mg alloy to study the cell proliferation behaviour.208 A standard MTT assay was adopted to measure cell viability.202 ...
Photo-controlled degradation of PLGA/Ti(3)C(2) hybrid coating on Mg-Sr alloy using near infrared light
2
2021
... Cytotoxicity testing is one of the biological evaluation and screening tests that uses tissue cells in vitro to observe the effects of medical implants on cell growth, reproduction and morphology.197 It is an important indicator for quickly evaluating the biocompatibility of implants because it is fast, simple and highly sensitive. Three types of cytotoxicity test are specified in ISO 10993:198 extract, direct contact and indirect contact tests. The extract test is suitable for evaluating the toxicity of soluble substances released from implants. The direct contact test is the most sensitive and can be used to measure even weak cytotoxicity.199 The indirect contact test is used on implants with high toxicity and/or small molecular weight.200, 201 Bone marrow-derived mesenchymal stromal cells, murine fibroblast cells (L-929) and murine calvarial preosteoblasts (MC3T3-E1) are commonly used for cytotoxicity studies.202-207 The cytotoxicity assay includes cell adhesion, cell viability and proliferation assessments. Cell morphology can be viewed by fluorescence staining under an inverted fluorescence microscope. In order to investigate cell adhesion, samples seeded with MC3T3-E1 pre-osteoblasts were rinsed with phosphate-buffered saline (PBS).207 MC3T3-E1 cells were directly seeded onto Mg alloy to study the cell proliferation behaviour.208 A standard MTT assay was adopted to measure cell viability.202 ...
... 202 ...
Photothermy-strengthened photocatalytic activity of polydopamine-modified metal-organic frameworks for rapid therapy of bacteria-infected wounds
2021
Degradability and in vivo biocompatibility of doped magnesium phosphate bioceramic scaffolds
2020
Quantitative assessment of degradation, cytocompatibility, and in vivo bone regeneration of silicon-incorporated magnesium phosphate bioceramics
2019
In vitro and in vivo biodegradation and biocompatibility of an MMT/BSA composite coating upon magnesium alloy AZ31
2020
A functionalized TiO(2)/Mg(2)TiO(4) nano-layer on biodegradable magnesium implant enables superior bone-implant integration and bacterial disinfection
2
2019
... Cytotoxicity testing is one of the biological evaluation and screening tests that uses tissue cells in vitro to observe the effects of medical implants on cell growth, reproduction and morphology.197 It is an important indicator for quickly evaluating the biocompatibility of implants because it is fast, simple and highly sensitive. Three types of cytotoxicity test are specified in ISO 10993:198 extract, direct contact and indirect contact tests. The extract test is suitable for evaluating the toxicity of soluble substances released from implants. The direct contact test is the most sensitive and can be used to measure even weak cytotoxicity.199 The indirect contact test is used on implants with high toxicity and/or small molecular weight.200, 201 Bone marrow-derived mesenchymal stromal cells, murine fibroblast cells (L-929) and murine calvarial preosteoblasts (MC3T3-E1) are commonly used for cytotoxicity studies.202-207 The cytotoxicity assay includes cell adhesion, cell viability and proliferation assessments. Cell morphology can be viewed by fluorescence staining under an inverted fluorescence microscope. In order to investigate cell adhesion, samples seeded with MC3T3-E1 pre-osteoblasts were rinsed with phosphate-buffered saline (PBS).207 MC3T3-E1 cells were directly seeded onto Mg alloy to study the cell proliferation behaviour.208 A standard MTT assay was adopted to measure cell viability.202 ...
... 207 MC3T3-E1 cells were directly seeded onto Mg alloy to study the cell proliferation behaviour.208 A standard MTT assay was adopted to measure cell viability.202 ...
In-vitro and in-vivo evaluation of strontium doped calcium phosphate coatings on biodegradable magnesium alloy for bone applications
1
2020
... Cytotoxicity testing is one of the biological evaluation and screening tests that uses tissue cells in vitro to observe the effects of medical implants on cell growth, reproduction and morphology.197 It is an important indicator for quickly evaluating the biocompatibility of implants because it is fast, simple and highly sensitive. Three types of cytotoxicity test are specified in ISO 10993:198 extract, direct contact and indirect contact tests. The extract test is suitable for evaluating the toxicity of soluble substances released from implants. The direct contact test is the most sensitive and can be used to measure even weak cytotoxicity.199 The indirect contact test is used on implants with high toxicity and/or small molecular weight.200, 201 Bone marrow-derived mesenchymal stromal cells, murine fibroblast cells (L-929) and murine calvarial preosteoblasts (MC3T3-E1) are commonly used for cytotoxicity studies.202-207 The cytotoxicity assay includes cell adhesion, cell viability and proliferation assessments. Cell morphology can be viewed by fluorescence staining under an inverted fluorescence microscope. In order to investigate cell adhesion, samples seeded with MC3T3-E1 pre-osteoblasts were rinsed with phosphate-buffered saline (PBS).207 MC3T3-E1 cells were directly seeded onto Mg alloy to study the cell proliferation behaviour.208 A standard MTT assay was adopted to measure cell viability.202 ...
1
... The degradation rate of Mg alloys determines the ion release rate in the physiological environment. The amount of released elements significantly affects the biocompatibility of the Mg alloys. An evaluation of the biosafety of Mg implants must be performed. Currently, preparation of the extracts from medical devices for cytotoxicity testing needs to follow Parts 5 and 12 of ISO 10993.198, 209 However, Mg alloys can react with an aqueous environment, release Mg ions and produce a higher pH value and osmolality in the surrounding medium,186 which is significantly affected by the constituents of the medium.210 In order to mimic an in vivo environment, a cell culture medium supplemented with serum is recommended.211 Wang et al.212 proposed a modified cytotoxicity testing standard for biodegradable Mg-based materials: a minimum 6-fold to a maximum 10-fold dilution of extracts from Mg implants for cytotoxicity tests. It has been reported that the test conditions can significantly influence the cytotoxicity testing of biodegradable metallic materials, which further suggested that the test conditions need to be carefully specified and different studies need to be cautiously compared.213 ...
Effect of inorganic salts, amino acids and proteins on the degradation of pure magnesium in vitro
1
2009
... The degradation rate of Mg alloys determines the ion release rate in the physiological environment. The amount of released elements significantly affects the biocompatibility of the Mg alloys. An evaluation of the biosafety of Mg implants must be performed. Currently, preparation of the extracts from medical devices for cytotoxicity testing needs to follow Parts 5 and 12 of ISO 10993.198, 209 However, Mg alloys can react with an aqueous environment, release Mg ions and produce a higher pH value and osmolality in the surrounding medium,186 which is significantly affected by the constituents of the medium.210 In order to mimic an in vivo environment, a cell culture medium supplemented with serum is recommended.211 Wang et al.212 proposed a modified cytotoxicity testing standard for biodegradable Mg-based materials: a minimum 6-fold to a maximum 10-fold dilution of extracts from Mg implants for cytotoxicity tests. It has been reported that the test conditions can significantly influence the cytotoxicity testing of biodegradable metallic materials, which further suggested that the test conditions need to be carefully specified and different studies need to be cautiously compared.213 ...
Improved cytotoxicity testing of magnesium materials
1
2011
... The degradation rate of Mg alloys determines the ion release rate in the physiological environment. The amount of released elements significantly affects the biocompatibility of the Mg alloys. An evaluation of the biosafety of Mg implants must be performed. Currently, preparation of the extracts from medical devices for cytotoxicity testing needs to follow Parts 5 and 12 of ISO 10993.198, 209 However, Mg alloys can react with an aqueous environment, release Mg ions and produce a higher pH value and osmolality in the surrounding medium,186 which is significantly affected by the constituents of the medium.210 In order to mimic an in vivo environment, a cell culture medium supplemented with serum is recommended.211 Wang et al.212 proposed a modified cytotoxicity testing standard for biodegradable Mg-based materials: a minimum 6-fold to a maximum 10-fold dilution of extracts from Mg implants for cytotoxicity tests. It has been reported that the test conditions can significantly influence the cytotoxicity testing of biodegradable metallic materials, which further suggested that the test conditions need to be carefully specified and different studies need to be cautiously compared.213 ...
Recommendation for modifying current cytotoxicity testing standards for biodegradable magnesium-based materials
1
2015
... The degradation rate of Mg alloys determines the ion release rate in the physiological environment. The amount of released elements significantly affects the biocompatibility of the Mg alloys. An evaluation of the biosafety of Mg implants must be performed. Currently, preparation of the extracts from medical devices for cytotoxicity testing needs to follow Parts 5 and 12 of ISO 10993.198, 209 However, Mg alloys can react with an aqueous environment, release Mg ions and produce a higher pH value and osmolality in the surrounding medium,186 which is significantly affected by the constituents of the medium.210 In order to mimic an in vivo environment, a cell culture medium supplemented with serum is recommended.211 Wang et al.212 proposed a modified cytotoxicity testing standard for biodegradable Mg-based materials: a minimum 6-fold to a maximum 10-fold dilution of extracts from Mg implants for cytotoxicity tests. It has been reported that the test conditions can significantly influence the cytotoxicity testing of biodegradable metallic materials, which further suggested that the test conditions need to be carefully specified and different studies need to be cautiously compared.213 ...
Test conditions can significantly affect the results of in vitro cytotoxicity testing of degradable metallic biomaterials
1
2021
... The degradation rate of Mg alloys determines the ion release rate in the physiological environment. The amount of released elements significantly affects the biocompatibility of the Mg alloys. An evaluation of the biosafety of Mg implants must be performed. Currently, preparation of the extracts from medical devices for cytotoxicity testing needs to follow Parts 5 and 12 of ISO 10993.198, 209 However, Mg alloys can react with an aqueous environment, release Mg ions and produce a higher pH value and osmolality in the surrounding medium,186 which is significantly affected by the constituents of the medium.210 In order to mimic an in vivo environment, a cell culture medium supplemented with serum is recommended.211 Wang et al.212 proposed a modified cytotoxicity testing standard for biodegradable Mg-based materials: a minimum 6-fold to a maximum 10-fold dilution of extracts from Mg implants for cytotoxicity tests. It has been reported that the test conditions can significantly influence the cytotoxicity testing of biodegradable metallic materials, which further suggested that the test conditions need to be carefully specified and different studies need to be cautiously compared.213 ...
In vivo study of nanostructured diopside (CaMgSi2O6) coating on magnesium alloy as biodegradable orthopedic implants
1
2014
... Mg is an essential ion in metabolism and can encourage bone growth, which helps the proper fixation of an implant into the host bone and potentially allows full healing of bone defects after degradation.186, 214 Importantly, biomaterials need to be designed to be bioactive and/or bioresorbable to improve tissue growth. Therefore, a biodegradable Mg alloy with great biocompatibility can make an ideal implant for load-bearing orthopaedic applications. Complex and/or customised shapes consistent with specific patient needs are required in real clinics nowadays. Thus, additive manufacturing is assuming greater and greater importance for implant manufacture, including for Mg. In addition, the influence of local pH changes on the adjacent tissue, evolution of hydrogen gas and the concentration of released metallic ions caused by bulk Mg-based implants can be reduced by adopting Mg scaffolds due to the smaller volume of implant. Furthermore, a material with porosity changing across the volume (a functionally-graded material) is currently believed to improve osseo-integration.215 This can be achieved by an additively-manufactureld scaffold. These unique features suggest that additively-manufactureld Mg scaffolds with bone-mimicking characteristics will become promising orthopaedic implants, possessing sufficient mechanical strength and ductility, low elastic modulus, excellent biocompatibility, and a complex shape. ...
1
2017
... Mg is an essential ion in metabolism and can encourage bone growth, which helps the proper fixation of an implant into the host bone and potentially allows full healing of bone defects after degradation.186, 214 Importantly, biomaterials need to be designed to be bioactive and/or bioresorbable to improve tissue growth. Therefore, a biodegradable Mg alloy with great biocompatibility can make an ideal implant for load-bearing orthopaedic applications. Complex and/or customised shapes consistent with specific patient needs are required in real clinics nowadays. Thus, additive manufacturing is assuming greater and greater importance for implant manufacture, including for Mg. In addition, the influence of local pH changes on the adjacent tissue, evolution of hydrogen gas and the concentration of released metallic ions caused by bulk Mg-based implants can be reduced by adopting Mg scaffolds due to the smaller volume of implant. Furthermore, a material with porosity changing across the volume (a functionally-graded material) is currently believed to improve osseo-integration.215 This can be achieved by an additively-manufactureld scaffold. These unique features suggest that additively-manufactureld Mg scaffolds with bone-mimicking characteristics will become promising orthopaedic implants, possessing sufficient mechanical strength and ductility, low elastic modulus, excellent biocompatibility, and a complex shape. ...
Laser additive manufacturing of Zn-2Al part for bone repair: Formability, microstructure and properties
1
2019
... Over recent decades, new types of biodegradable Mg alloys have mainly been developed by casting because it is easy to regulate the alloying elements. However casting generally leads to large grains, which need subsequent deformation (such as extrusion, rolling and forging) to reduce their size. In particular, severe plastic deformation has been widely used to obtain fine grains and therefore further tailor the mechanical and corrosion performance. In contrast, additive manufacturing involves rapid melting and solidification which results directly in a fine microstructure. This technique also shows an ability to regulate the second phase distribution and composition, because the alloy elements mainly dissolve in the matrix due to the fast advanced solid/liquid frontier (‘solute capture effect’).216 The reduced second phase caused by the extended solid solution of alloying elements may result in improved corrosion resistance because of the reduced galvanic corrosion effect. ...
Nutrition in bone health revisited: a story beyond calcium
1
2000
... Alloying is still the critical factor determining the biocompatibility, mechanical properties and biodegradation behaviour of orthopaedic implant materials. Firstly, the toxicity of alloying elements in the biological environment needs to be carefully considered. Some nutrient alloying elements are good candidates. For example, Zn is recognised as a nutritionally-essential element in the human body. Ca is a major component of human bone and is an important element in cell signalling; released ions are beneficial for bone healing.217 Sr belongs to Group IIA of the periodic table (the same as Mg) and shares similar chemical, biological and metallurgical properties, which can stimulate bone cell differentiation and inhibit bone resorption.218 Zr is known to be of low toxicity to living organisms and to have a stimulating effect on bone cells, which can improve bone integration.219 ...
Strontium ranelate treatment of human primary osteoblasts promotes an osteocyte-like phenotype while eliciting an osteoprotegerin response
1
2009
... Alloying is still the critical factor determining the biocompatibility, mechanical properties and biodegradation behaviour of orthopaedic implant materials. Firstly, the toxicity of alloying elements in the biological environment needs to be carefully considered. Some nutrient alloying elements are good candidates. For example, Zn is recognised as a nutritionally-essential element in the human body. Ca is a major component of human bone and is an important element in cell signalling; released ions are beneficial for bone healing.217 Sr belongs to Group IIA of the periodic table (the same as Mg) and shares similar chemical, biological and metallurgical properties, which can stimulate bone cell differentiation and inhibit bone resorption.218 Zr is known to be of low toxicity to living organisms and to have a stimulating effect on bone cells, which can improve bone integration.219 ...
Enhanced antibacterial properties, biocompatibility, and corrosion resistance of degradable Mg-Nd-Zn-Zr alloy
1
2015
... Alloying is still the critical factor determining the biocompatibility, mechanical properties and biodegradation behaviour of orthopaedic implant materials. Firstly, the toxicity of alloying elements in the biological environment needs to be carefully considered. Some nutrient alloying elements are good candidates. For example, Zn is recognised as a nutritionally-essential element in the human body. Ca is a major component of human bone and is an important element in cell signalling; released ions are beneficial for bone healing.217 Sr belongs to Group IIA of the periodic table (the same as Mg) and shares similar chemical, biological and metallurgical properties, which can stimulate bone cell differentiation and inhibit bone resorption.218 Zr is known to be of low toxicity to living organisms and to have a stimulating effect on bone cells, which can improve bone integration.219 ...
Medical Devices Business Services, I. 3.5mm, 4.5mm Locking Compression Plate (LCP®)
1
2021
... Thirdly, for bone implants, 3﹣4 months is required from fracture callus formation to new bone formation and eventually solid bone healing to restore most of the bone’s original strength. For example, when the dimensions of a locking compression plate (locking compression plate 3.5﹣423.621 from Depuy Synthes220) are 163 mm × 10 mm × 2 mm (volume of 3.84 cm3 determined by micro-computed tomography), the degradation rate needs to be controlled to be below 0.97 mm/year which would correspond to complete degradation in 3 months according to equation (6). The biodegradation properties can be tailored by adjusting the alloying treatment, grain refinement, the formation of a passivation film, reduction in the cathode-anode potential difference and secondary phase amount and distribution. The elements Nd and Y are good candidates which can significantly improve the mechanical performance of Mg alloys by grain refinement strengthening, solid solution strengthening and precipitate strengthening.221 They also can greatly decrease the corrosion rate by removing impurities, creating less noble intermetallic phases (‘scavenger effect’ on impurities) and forming stable protective films.222 However the concentrations of Nd and Y need to be carefully controlled below the threshold level (e.g. < 5wt% depending on the actual component). ...
As cast microstructures on the mechanical and corrosion behaviour of ZK40 modified with Gd and Nd additions
1
2017
... Thirdly, for bone implants, 3﹣4 months is required from fracture callus formation to new bone formation and eventually solid bone healing to restore most of the bone’s original strength. For example, when the dimensions of a locking compression plate (locking compression plate 3.5﹣423.621 from Depuy Synthes220) are 163 mm × 10 mm × 2 mm (volume of 3.84 cm3 determined by micro-computed tomography), the degradation rate needs to be controlled to be below 0.97 mm/year which would correspond to complete degradation in 3 months according to equation (6). The biodegradation properties can be tailored by adjusting the alloying treatment, grain refinement, the formation of a passivation film, reduction in the cathode-anode potential difference and secondary phase amount and distribution. The elements Nd and Y are good candidates which can significantly improve the mechanical performance of Mg alloys by grain refinement strengthening, solid solution strengthening and precipitate strengthening.221 They also can greatly decrease the corrosion rate by removing impurities, creating less noble intermetallic phases (‘scavenger effect’ on impurities) and forming stable protective films.222 However the concentrations of Nd and Y need to be carefully controlled below the threshold level (e.g. < 5wt% depending on the actual component). ...
A Comparison of corrosion behavior in saline environment: rare earth metals (Y, Nd, Gd, Dy) for alloying of biodegradable magnesium alloys
1
2013
... Thirdly, for bone implants, 3﹣4 months is required from fracture callus formation to new bone formation and eventually solid bone healing to restore most of the bone’s original strength. For example, when the dimensions of a locking compression plate (locking compression plate 3.5﹣423.621 from Depuy Synthes220) are 163 mm × 10 mm × 2 mm (volume of 3.84 cm3 determined by micro-computed tomography), the degradation rate needs to be controlled to be below 0.97 mm/year which would correspond to complete degradation in 3 months according to equation (6). The biodegradation properties can be tailored by adjusting the alloying treatment, grain refinement, the formation of a passivation film, reduction in the cathode-anode potential difference and secondary phase amount and distribution. The elements Nd and Y are good candidates which can significantly improve the mechanical performance of Mg alloys by grain refinement strengthening, solid solution strengthening and precipitate strengthening.221 They also can greatly decrease the corrosion rate by removing impurities, creating less noble intermetallic phases (‘scavenger effect’ on impurities) and forming stable protective films.222 However the concentrations of Nd and Y need to be carefully controlled below the threshold level (e.g. < 5wt% depending on the actual component). ...
Biodegradation-affected fatigue behavior of additively manufactured porous magnesium
1
2019
... Currently, some Mg alloys such as WE43,165, 223 AZ91,224 Mg-9wt% Al225 and ZK60226-228 are fabricated using laser additive manufacturing. The in vitro static degradation behaviour has been studied.165, 226, 229, 230 However, the in vivo response, especially the dynamic biodegradation including geometric and mechanical changes, have been barely reported. The dynamic degradation of Mg leads to varied biological interactions and mechanical performance. Therefore, the dynamic evolution of Mg implants in the physiological environment needs to be investigated, including changes in the implant shape, variations in the mechanical strength and elastic modulus, pH variation, the release of corrosion products, the amount of released metallic ions, hydrogen gas and the changed biocompatibility. In addition, the related modelling, which can accurately simulate the dynamic physiological-chemical-mechanical variation during the biodegradation process along with bone healing, needs development. ...
Effect of energy input on formability, microstructure and mechanical properties of selective laser melted AZ91D magnesium alloy
1
2014
... Currently, some Mg alloys such as WE43,165, 223 AZ91,224 Mg-9wt% Al225 and ZK60226-228 are fabricated using laser additive manufacturing. The in vitro static degradation behaviour has been studied.165, 226, 229, 230 However, the in vivo response, especially the dynamic biodegradation including geometric and mechanical changes, have been barely reported. The dynamic degradation of Mg leads to varied biological interactions and mechanical performance. Therefore, the dynamic evolution of Mg implants in the physiological environment needs to be investigated, including changes in the implant shape, variations in the mechanical strength and elastic modulus, pH variation, the release of corrosion products, the amount of released metallic ions, hydrogen gas and the changed biocompatibility. In addition, the related modelling, which can accurately simulate the dynamic physiological-chemical-mechanical variation during the biodegradation process along with bone healing, needs development. ...
Effects of processing parameters on properties of selective laser melting Mg-9%Al powder mixture
1
2012
... Currently, some Mg alloys such as WE43,165, 223 AZ91,224 Mg-9wt% Al225 and ZK60226-228 are fabricated using laser additive manufacturing. The in vitro static degradation behaviour has been studied.165, 226, 229, 230 However, the in vivo response, especially the dynamic biodegradation including geometric and mechanical changes, have been barely reported. The dynamic degradation of Mg leads to varied biological interactions and mechanical performance. Therefore, the dynamic evolution of Mg implants in the physiological environment needs to be investigated, including changes in the implant shape, variations in the mechanical strength and elastic modulus, pH variation, the release of corrosion products, the amount of released metallic ions, hydrogen gas and the changed biocompatibility. In addition, the related modelling, which can accurately simulate the dynamic physiological-chemical-mechanical variation during the biodegradation process along with bone healing, needs development. ...
Laser rapid solidification improves corrosion behavior of Mg-Zn-Zr alloy
2
2017
... Currently, some Mg alloys such as WE43,165, 223 AZ91,224 Mg-9wt% Al225 and ZK60226-228 are fabricated using laser additive manufacturing. The in vitro static degradation behaviour has been studied.165, 226, 229, 230 However, the in vivo response, especially the dynamic biodegradation including geometric and mechanical changes, have been barely reported. The dynamic degradation of Mg leads to varied biological interactions and mechanical performance. Therefore, the dynamic evolution of Mg implants in the physiological environment needs to be investigated, including changes in the implant shape, variations in the mechanical strength and elastic modulus, pH variation, the release of corrosion products, the amount of released metallic ions, hydrogen gas and the changed biocompatibility. In addition, the related modelling, which can accurately simulate the dynamic physiological-chemical-mechanical variation during the biodegradation process along with bone healing, needs development. ...
... , 226, 229, 230 However, the in vivo response, especially the dynamic biodegradation including geometric and mechanical changes, have been barely reported. The dynamic degradation of Mg leads to varied biological interactions and mechanical performance. Therefore, the dynamic evolution of Mg implants in the physiological environment needs to be investigated, including changes in the implant shape, variations in the mechanical strength and elastic modulus, pH variation, the release of corrosion products, the amount of released metallic ions, hydrogen gas and the changed biocompatibility. In addition, the related modelling, which can accurately simulate the dynamic physiological-chemical-mechanical variation during the biodegradation process along with bone healing, needs development. ...
Influence of element vaporization on formability, composition, microstructure, and mechanical performance of the selective laser melted Mg-Zn-Zr components
2015
Additive manufacturing of magnesium-zinc-zirconium (ZK) alloys via capillary-mediated binderless three-dimensional printing
1
2019
... Currently, some Mg alloys such as WE43,165, 223 AZ91,224 Mg-9wt% Al225 and ZK60226-228 are fabricated using laser additive manufacturing. The in vitro static degradation behaviour has been studied.165, 226, 229, 230 However, the in vivo response, especially the dynamic biodegradation including geometric and mechanical changes, have been barely reported. The dynamic degradation of Mg leads to varied biological interactions and mechanical performance. Therefore, the dynamic evolution of Mg implants in the physiological environment needs to be investigated, including changes in the implant shape, variations in the mechanical strength and elastic modulus, pH variation, the release of corrosion products, the amount of released metallic ions, hydrogen gas and the changed biocompatibility. In addition, the related modelling, which can accurately simulate the dynamic physiological-chemical-mechanical variation during the biodegradation process along with bone healing, needs development. ...
Microstructure evolution and biodegradation behavior of laser rapid solidified Mg-Al-Zn alloy
1
2017
... Currently, some Mg alloys such as WE43,165, 223 AZ91,224 Mg-9wt% Al225 and ZK60226-228 are fabricated using laser additive manufacturing. The in vitro static degradation behaviour has been studied.165, 226, 229, 230 However, the in vivo response, especially the dynamic biodegradation including geometric and mechanical changes, have been barely reported. The dynamic degradation of Mg leads to varied biological interactions and mechanical performance. Therefore, the dynamic evolution of Mg implants in the physiological environment needs to be investigated, including changes in the implant shape, variations in the mechanical strength and elastic modulus, pH variation, the release of corrosion products, the amount of released metallic ions, hydrogen gas and the changed biocompatibility. In addition, the related modelling, which can accurately simulate the dynamic physiological-chemical-mechanical variation during the biodegradation process along with bone healing, needs development. ...
Biodegradation mechanisms of selective laser-melted Mg-xAl-Zn alloy: grain size and intermetallic phase
1
2018
... Currently, some Mg alloys such as WE43,165, 223 AZ91,224 Mg-9wt% Al225 and ZK60226-228 are fabricated using laser additive manufacturing. The in vitro static degradation behaviour has been studied.165, 226, 229, 230 However, the in vivo response, especially the dynamic biodegradation including geometric and mechanical changes, have been barely reported. The dynamic degradation of Mg leads to varied biological interactions and mechanical performance. Therefore, the dynamic evolution of Mg implants in the physiological environment needs to be investigated, including changes in the implant shape, variations in the mechanical strength and elastic modulus, pH variation, the release of corrosion products, the amount of released metallic ions, hydrogen gas and the changed biocompatibility. In addition, the related modelling, which can accurately simulate the dynamic physiological-chemical-mechanical variation during the biodegradation process along with bone healing, needs development. ...