Corrosion Resistance, Biocompatibility and Mechanical Behavior of Magnesium Based Alloys for Use in Medical Implant Applications

Biomaterials including ceramic material, polymer material, metallic material and composite material have been used in biomedical scaffolds, artificial tissues and drug delivery systems for a long time. Metallic biomaterials such as stainless steels, cobalt-based alloys and titanium alloys are commonly used to assist in repairing or replacing damaged bone tissues. These materials are more suitable for load-bearing applications as compared to the ceramics or polymeric materials. This is due to their high mechanical strength and fracture toughness. A limitation of the metallic biomaterials currently in use is the possible release of toxic metal ions through the corrosion or wear processes leading to inflammation and tissue losses. Magnesium (Mg) and Mg-based alloys are a new generation of degradable metallic materials that have attracted great attention in the last ten years. There are several advantages of Mg-based alloys for bone orthopedic application over other metallic biomaterials, e.g. stainless steel, titanium alloys and cobalt-chromium alloys. First, Mg is an essential element for many biological activities including enzymatic reaction, formation of apatite, and bone cells adsorption. Second, their physical and mechanical properties including density, elastic modulus and compressive yield strength are much closer to that of natural bone, and therefore can avoid the stress shielding effect. Third, Mg alloys can eliminate the necessity of a second surgery to remove the permanent bone implants. Recent results show Mg alloyed with Al, Zn, Ca, Zirconium (Zr), Yttrium (Y) and rare earth elements can significantly improve the corrosion resistance and mechanical strength. This paper will review and compare the corrosion resistance, biocompatibilities and mechanical properties of current researched magnesium based alloys for use in medical implant applications.

کلیدواژه ها:

Metallic biomaterials ، mechanical strength ، corrosion or wear processes ، Mg-based alloys ، bone orthopedic application