Impact of hot rolling, Zn and Sn on the mechanical and corrosion characteristics of Mg-Zn-Ca alloys

Abstract

In this study, it was aimed to develop a biodegradable metallic plate that is an alternative to bioinert metal plates. The main advantage of using biodegradable materials for implants is that they can be gradually replaced with the patient's own tissue, which reduces the need for additional surgeries to remove the implant after it has served its purpose. Magnesium and its alloys can provide biocompatibility as orthopedic implant materials. Mg-Zn-Ca and Mg-Zn-Ca-Sn alloys were prepared using the gravity die casting method. Zn (1.0 wt% and 2.0 wt%) and Sn (0.0 wt%, 0.5 wt% and 1.0 wt%) ratios were used as variables, and the Ca ratio (0.3 wt%) was kept constant in all alloys. After homogenization heat treatment, alloys were hot rolled. Hot rolling resulted in grain refinement, much higher yield and tensile strength, and hardness at the expense of the lower strain. However, hot rolling had a detrimental impact on the corrosion resistance of the alloys. Among the alloys, ZX20-h alloy showed the highest yield and tensile strength before and after corrosion tests. The lowest corrosion rate was measured in ZXT200 alloy as 5.1 mm∙year‒1 after 10 day of immersion. Although ZX20-h alloy has a higher corrosion rate (13.56 mm∙year‒1) than ZXT200 alloy, it can be improved further to be used as biodegradable bone support plate material.