Formation of nano-sized compounds during friction stir welding of Cu–Zn alloys: effect of tool composition

Abstract

For the first time, the origin of tool composition effect on microstructure and mechanical properties of the friction stir welded joints has been disclosed. For this aim, nanoindentation, orientation image microscopy, and transmission electron microscopy were employed to analyze the microstructure and mechanical properties in the case of copperzinc alloy joints welded by different tool compositions. The results showed that the nanosized intermetallic compounds were formed in the stir zone when using a hot-work steel tool, which increased the strength of the joint. The outcomes of this work can be used to modify the friction stir welded joints of various metals and alloys.