Friction Stir Welding of AZ31 Mg Alloy: Microstructure, Micro hardness and Electrochemical Behavior

Abstract

In this investigation, rolled plates of AZ31 Mg alloy were successfully friction-stir welded. It was found that the process leads to the microstructural refinement in the NZ due to the dynamic recrystallization with a global microstructural heterogeneity through the weld. The maximum microhardness values were attributed to the finest microstructure. The obtained results revealed that the cathodic behavior of the grain boundaries improves the corrosion resistance of the NZ. Thus, the corrosion resistance enhancement was ascribed to the most homogeneous microstructure and the finest grains.