Systemically study of microstructure, mechanical and corrosion properties in biodegradable Zn-0.5Mn-0.2Mg alloys by rolling and heat treatment

Abstract

In this study, Zn-0.5Mn-0.2Mg alloys were prepared by hot-rolled and heat-treated at 100–300 °C. The microstructure, mechanical and corrosion properties were systemically investigated. It was found that the MnZn_13, Mg₂Zn₁₁ second phases and texture are similar for the rolled and heat-treatment sample, but the grain size increased from 1.64 μm to 11.24 μm with the increasing heat-treatment temperature. The tensile strength increased and ductility decreased after heat treatment, and the maximum strength of 305 MPa was obtained at 300 °C. The improved strength was mainly attributed to the increased grain size which reduced the dominant grain boundary slip. Another result is that the localized corrosion phenomenon is reduced after heat treatment, especially for 200 °C heat-treated sample. In addition, the heat treatment has not deteriorated the cell viability of L-929 and shows no-toxicity in 25 % extract. The study demonstrates that heat treatment after rolling is a promising approach to improve the comprehensive properties of biodegradable Zn alloys.