Effect of Multipass Friction Stir Processing on Surface Corrosion Resistance and Wear Resistance of ZK60 Alloy

Abstract

Multipass friction stir processing (FSP) can result in a homogeneous microstructure and significant improvement in mechanical properties of magnesium alloys. Few studies have concentrated on the surface properties of Mg–Zn–Zr alloy during multipass FSP. The aim of this study was to investigate the microstructure evolutions as well as the effects on the surface corrosion and wear resistance of ZK60 plates during multipass FSP. An interesting finding is that FSP can significantly refine the grains and improve the surface properties of ZK60 alloy. However, subsequent passes of FSP cannot further reduce the grain size in the stir zone, but they cause an increase in the grain size in the ZK60 alloy. In addition, the subsequent passes of FSP are not beneficial, but rather are, harmful to the corrosion resistance of ZK60 alloy. There is little positive effect on the improvement in the wear resistance of ZK60 plates.