Microstructre and mechanical properties of Mg/Al joints by pulse MIG assisted induction pre-heating with composite interlayers

Butt Joints of AZ31 magnesium alloys and Al1060 aluminium plates were produced by conventional MIG welding process with composite interlayers composed of zinc, copper and aluminium foil and induction pre-heating method was used to promote the melting degree of the high melting interlayers, which achieved the connection of dissimilar materials effectively by comparison via SEM and tensile test. The results indicated that crack-free Al/Mg butt joints were obtained. The analysis of the microstructure of the joints showed that the phase composition at the interface between base metal and fusion zone related to the sequence of the different foils. The tensile strength of the joints could reach 21 MPa and the fracture located at the interfacial zone which was mainly composed of brittle Al-Mg compounds.