Microstructure Characterization and Mechanical Properties of Mg/Al Dissimilar Joints by Friction Stir Welding with Zn Interlayer

Abstract

The amount and shape of intermetallic compounds (IMCs) may influence the properties of the Al–Mg dissimilar welded joints. In the present study, friction stir welding (FSW) assisted with Zn interlayer was designed to weld Mg to Al alloys. The effects of the Zn interlayer on the microstructure and mechanical properties of the joints were studied in detail. The results indicated that Zn interlayer could improve performance of the joints and inhibit the formation of Mg/Al IMCs, which were replaced by Mg–Zn and Al–Zn solid solutions. The maximum tensile strength of the joint with Zn interlayer was 102 MPa, which was elevated about 27% compared with the joint without Zn interlayer.