Microstructure, mechanical and bio-corrosion properties of Mg-Zn-Zr alloys with minor Ca addition

In this research, effect of minor alloying element Ca on microstructure, mechanical and bio-corrosion properties of as-cast Mg-3Zn-0.3Zr-xCa (x=0, 0.3, 0.6, 0.9) alloys were investigated for biomedical application. The result showed that Ca played a dual role in mechanical properties and corrosion resistance. With minor Ca addition, the microstructure of the alloy is significantly refined and more uniform. The elongation, tensile strength and corrosion resistance of the studied alloys increases and then decreases with the increase of Ca content. With increasing the Ca content to 0.6wt-%, the new strip phase of Ca2Mg6Zn3 can be found, and gives the best strength and corrosion resistance. It was thought that the alteration of the second phase and the microstructure affect the mechanical and bio-corrosion properties.