Effect of ECAP Deformation on Microstructure and Corrosion Properties of High Strength-ductility Mg-Sn-Zn-Zr Alloys

Mg alloys as biodegradable metal materials have wide application potential in the treatment of orthopedic and cardiovascular diseases, but its shortcomings such as fast degradation rate and insufficient mechanical properties affect its further practical applications. Equal channel angular pressing（ECAP） technology can significantly improve the mechanical properties of Mg alloys. In order to study its effect on the corrosion behavior of Mg alloys, the corrosion behavior of high strength-ductility Mg-Sn-Zn-Zr（TZK） alloy in Hank’s solution under different deformation passes（1-4） were investigated using OM, SEM, immersion weight loss method and electrochemical workstation. The results show that the corrosion rate of the alloy decreases first and then increases with the increase of extrusion pass, and the corrosion products change from needle-like to dense spherical. After three passes of deformation, the alloy has the smallest average grain size of 2.13 μm, the smallest hydrogen evolution rate, corrosion rate and corrosion current density, which indicates that the corrosion resistance of the TZK alloy is the best.