Formation and Distribution Mechanism of Intermetallic Compounds of Al/Mg Joint with Zn Transition Metal

6061 Al alloy and AZ3IB Mg alloy were joined by lapping TIG welding process with Zn transition metal. Microstructrues and Micro-hardness in the fusion near the Mg substrate were examined. The formation and distribution mechanism of IMCs of Al/Mg joint, and the relationship of microstructure and mechanical property were discussed. The introduction of Zn transition metal reduces the Mg/Al IMCs effectively. The microstructure in the fusion zone near the Mg substrate composes of three regions. B zone contains of only MgZn2 IMCs. That is the place of highest micro-hardness in the weld seam. A and C zones characterize with solid solution precipitated on the MgZn2 basement which can enhance the ductility of Mg/Al joint. This result indicates that the distribtution of IMCs in the interfacial layer affected property of Mg/Al joint.