Microstructure, mechanical properties and biomedical application of medical implantable extruded Mg-Zn-Zr-Ca alloy

This study added Zn, Zr and Ca as alloying elements of magnesium alloy (ZKX500) and produced fine grain structure by extrusion process. After 2 h of homogenization, abnormal grain growth was avoided, stress relief, improvement of stability and reduction of element segregation are achieved. In addition, application of phosphate coating on homogenized ZKX500, the mechanism of coating degradation and mechanical properties after degradation were accomplished and determined that the corrosion resistance of ZKX500 can be enhanced by homogenization and phosphate coating. To further enclose clinical-applying condition, ZKX500 screw undergoes 2 h of homogenization and phosphate coating, then immersed in simulated body fluid (SBF). The degradation rate of ZKX500 screw meets application requirement, which demonstrated homogenization and phosphate coating improved degradation behavior and mechanical properties of ZKX500 screws and exhibited its potential of clinical application.