Joining of magnesium and aluminum via arc-assisted ultrasonic seam welding with Sn/Zn composite interlayer

Mg and Al alloys were successfully joined via a novel arc-assisted ultrasonic seam welding technique with Sn/Zn composite interlayer. Effects of Sn/Zn composite interlayer on the microstructure and mechanical properties of the joints were investigated in detail. The results indicated that Mg2Sn, Sn-based solid solution and Mg-based solid solution were formed at Mg/Sn interface while Al-based solid solution and Zn-based solid solution were formed at Al/Zn interface. The addition of Sn/Zn composite interlayer could suppress the formation of brittle Mg-Al intermetallic compounds and improve the mechanical properties of the joints obviously. The average peak load of the joints with Sn/Zn composite interlayer was 2.5kN, which was 150% increase over the joints without Sn/Zn composite interlayer. The joints fractured roughly in Mg substrate rather than Mg/Al interface.