Influence of Zirconium (Zr) on the microstructure, mechanical properties and corrosion behavior of biodegradable zinc-magnesium alloys

Abstract Zinc (Zn)-based alloys have been investigated as one kind of promising degradable metallic biomaterials. Nevertheless, the mechanical and corrosion properties of Zn alloys still need to be improved to meet the demands of biodegradable implants. In this study, Zn1Mg alloy (1 wt%) was studied as the base alloy with adding varied amounts of zirconium (Zr), and both casting and extrusion were employed to treat the developed alloys. The results revealed that the addition of Zr refined the microstructure of Zn1Mg, which consisted of Zn primary dendrite, eutectic mixtures of Zn and Mg2Zn11, and a new formed particle precipitation (Zn22Zr). The finer microstructure accordingly improved the mechanical properties and the corrosion resistance of the alloys. Although the effect of Zr on the mechanical properties was largely minimized by extrusion process, Zr further enhanced the corrosion resistance and led to more uniform corrosion for the extruded alloys.