Medical implant applications alloy development

Another potential application of Mg alloys is in the medical field where Mg alloys may be used as a biodegradable implant material. The biocompatibility of Mg was first known in the early twentieth century. However, the intrinsic rapid corrosion and hydrogen evolution phenomena associated with Mg forced researchers to give up the first clinical trials. Recently, a greater understanding of corrosion mechanisms and development of innovative corrosion protection techniques are reviving the research interest in biodegradable Mg alloys. 

During the last 30 years, advances in material science have led to the development of synthetic materials that have unique properties for medical applications. Metals, ceramics, polymers, composites are the main classes of synthetic biomaterials. Metals and their alloys have been used in various forms as implants and for hard tissue repair (e.g., dental implants, joint replacement, fracture plates, screws, pins). They are mechanically strong, tough and ductile. They can be readily fabricated and sterilised. However, they may corrode in the biological media, their densities are high and their mechanical properties mismatch with bone, which may result undesirable destruction of the surrounding hard tissues. 

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