Optimization and analysis of sustainable magnesium-based alloy (Mg-Zn-Ca-Y) for biomedical applications

Due to strength and biodegradability, magnesium (Mg) and its alloys are potential biodegradable implant materials. However, pure Mg corrodes more rapidly in the physiological environment, causing rapid deterioration before bone repair. The discrepancy between bone healing and Mg implant deterioration encourages the development of new Mg alloys with other acceptable alloying elements to achieve the desired high corrosion resistance and mechanical properties. In this work, different concentrations of yttrium (Y), that is, Mg-4zn-0.2ca-xY, (x= 3,6,9,12% wt), are added to Mg-based alloys. The microstructure, mechanical characteristics, corrosion behavior, and biocompatibility of the alloys were carefully investigated. When Y concentrations are high, Mg alloys with Y change significantly. High Y concentrations in Mg alloys containing yttrium (Y) suppress intermetallic phases along grain boundaries and form chemically stable Y oxide layers on the surfaces, changing their microstructures and improving their corrosion resistance. Cytotoxicity analysis showed that human osteoblast cells were not significantly affected by the Y-containing Mg alloys. The benefits of using Y as an alloying element to simultaneously adjust Mg alloys with higher strength and slower deterioration are presented.