Microstructure, Mechanical Properties and In Vitro Degradation Behavior of a Novel Biodegradable Mg-1.5Zn-0.6Zr-0.2Sc Alloy

A novel Mg-1.5Zn-0.6Zr-0.2Sc (denoted as ZK21-0.2Sc) alloy was developed as potential biodegradable implant materials. The microstructure, mechanical properties, and in vitro degradation behavior of the as-cast ZK21-0.2Sc alloy were investigated and compared with ZK21 alloy and pure Mg. The ZK21-0.2Sc alloy showed a single-phase structure with fine equiaxed grains. The alloy exhibited a good balance between strength and ductility. Both immersion tests and electrochemical tests showed that the ZK21-0.2Sc alloy had the lowest degradation rate in Hank's solution. The excellent degradation behavior of ZK21-0.2Sc alloy could be explained by the single-phase and fine grain structure, the more effective protection corrosion film, and the beneficial alloying effects of Zn, Zr and Sc.