Tailored Surfaces on Biomedical Magnesium Alloys via Novel Beam and Friction Based Manufacturing Processes: A Review

Magnesium based alloys are attractive materials for biomedical applications as a result of their similar properties to the human bone and vital nature of the Mg ions during various functions of the human body. However, these materials suffer from poor corrosion resistance in chloride containing physiological environments. As a result, surface modification of biomedical alloys is needed to not only enhance the corrosion resistance but also biointegration characteristics. The current review article mainly focuses on beam and friction stir based techniques for surface processing of biomedical Mg alloys and composites. Each technique is further divided into sub-methods. Under the beam based processing, surface melting and bioceramic coating synthesis are discussed in detail. In the case of friction based methods, friction stir processing for grain refinement and techniques of surface modification to produce surface bioceramic composites are discussed. Furthermore, latest developments in the area of beam as well as friction stir additive manufacturing of biomedical Mg alloys and composites are elucidated. Lastly, possible directions for future progress and scaling up the lab level developments to actual applications in these materials processing areas for biomedical Mg alloys are provided.