Effects of alloying elements and thermomechanical process on the mechanical and corrosion properties of biodegradable Mg alloys

In this study, four different Mg-Zn-Ca-Mn alloys were produced using gravity die casting method. Mn content was kept constant in all alloys, while Zn and Ca were added in two different ratios. Homogenization heat treatment was applied to all cast alloys and a specimen from each homogenized alloy was hot rolled. Microstructure, mechanical properties, and corrosion behavior of the homogenized and hot rolled alloys were investigated as comparatively. Following results were obtained; grain size decreased significantly with increasing Zn content, Zn promoted Ca2Mg6Zn3 phase formation, corrosion resistance increased with increasing Zn/Ca atomic ratio, hot rolling resulted in much higher tensile strength but much lower ductility and toughness. Among the homogenized and hot rolled alloys, ZXM300-h alloy (hot rolled ZXM300 alloy) with its 146 +/- 2.5 MPa yield strength, 229 +/- 3.7 MPa tensile strength,% 1.6 +/- 0.1 elongation and 0.029 mm/yr immersion corrosion rate exhibited the best mechanical properties and corrosion resistance to be used as a biodegradable alloy such as fracture bone plate material. (C) 2020 Published by Elsevier B.V. on behalf of Chongqing University.

Automated summary

The study found that the grain size of the alloy decreased significantly with increasing zinc content, leading to enhanced corrosion resistance. Hot rolled alloys exhibited higher tensile strength but lower ductility and toughness. The ZXM300-h alloy was identified to have the best mechanical properties and corrosion resistance, suitable for use as a biodegradable fracture bone plate material.