Microstructure, Biodegradation, and Mechanical Properties of Biodegradable Mg-Based Alloy Containing Calcium for Biomedical Applications

The influence of Ca on the microstructure characterization, mechanical performance, corrosion behavior, and cytocompatibility of Mg-Zn-Al magnesium alloy was studied. Mg-Zn-Al and Mg-Zn-Al-xCa alloys were evaluated as cast. Scanning electron microscopy demonstrated that the microstructure of the Ca-containing alloys was substantially finer and more uniform than the standard Mg-Zn-Al alloy. Hardness and compressive strength tests revealed that the addition of Ca boosted hardness and compressive strength while decreasing ductility. The corrosion resistance of the investigated alloys was enhanced initially but dropped as the Ca concentration increased. The corrosion resistance performance of Mg-Zn-Al-0.5Ca alloy was the best, with a corrosion rate of 3.7 mm/y due to the specific microstructure and dense products related to the corrosion on the sample surface. Cytotoxicity experiments showed that Mg-based alloys with a low Ca content have higher cell viability than Mg-Zn-Al and Mg-based alloys with a high Ca concentration, indicating improved biocompatibility. As a result, Mg-Zn-Al-0.5Ca alloys can be termed alloys with superior corrosion resistance and great mechanical properties that display high corrosion resistance as well as good biocompatibility.