Effect of Si, Mn, Sn on Tensile and Corrosion Properties of Mg-4Zn-0.5Ca Alloys for Biodegradable Implant Materials

Effect of elements Si, Mn, Sn on tensile and corrosion properties of Mg-4Zn-0.5Ca alloys were investigated. The results of tensile properties show that the yield strength, ultimate tensile strength and elongation of Mg-4Zn-0.5Ca alloy increased significantly with the addition of 0.6 wt% Mn. This is considered the grain refinement effect due to addition of Mn. However addition of 0.6 wt% Si decreased yield strength, ultimate tensile strength and elongation. The bio-corrosion behavior of Mg-4Zn-0.5Ca-X alloys were investigated using immersion tests and potentiodynamic polarization test in Hank's solution. Immersion test showed that corrosion rate of Mg-4Zn-0.5Ca-0.6Mn alloy was the lowest rate and addition of 1.0 wt% Sn accelerated corrosion rate due to micro-galvanic effect in alpha-Mg/CaMgSn phases interface. And corrosion potential (E-corr) of Mg-4Zn-0.5Ca-0.6Mn alloy was the most noble among Mg-4Zn-0.5Ca-X alloys.