Interfacial microstructure and mechanical property in friction stir welded Mg/Al joints under low rotation speed
Xuesong Fu, Ke Chen, Zhen Zhang, Katsuyoshi Kondoh, Min Wang, Xueming Hua
Abstract
The variation of interface microstructure along thickness direction and the associated effects on tensile strength were studied. Thin intermetallic compounds (IMC) layer, ranging from 700 nm to 2 μm, formed through solid-state diffusion instead of eutectic reaction under low rotation speed of 300 rev min −1 . It was consisted of Al 3 Mg 2 sublayer and Mg 17 Al 12 sublayer, with Mg 17 Al 12 sublayer thinner than Al 3 Mg 2 sublayer. IMC layer in the upper part is thinner than that in the middle part, and it is continuous in the upper and middle part while discontinuous near the bottom surface. Despite the difference in interface microstructure, the bonding strengths of upper part and middle part are similar, proving the important effects of macroscopic geometrical configuration of the interface.