Study On The Fusion Welding Process Of Magnesium Alloy And Aluminum Alloy With Zinc As Interlayer

With the wide application of the Magnesium alloys and Aluminum alloys，theproblem of joining Magnesium to Aluminum alloys brings people’s attention.Magnesium and Aluminum can be joined by diffusion welding and brazing，however，the shape and size of butt piece are hard to receive. The fusion welding isthe most common and economical welding method, if the joints of Magnesium andAluminum alloys can be achieved successfully by the fusion welding，which has thevital significance. In the welding procedure, the intermetallic compounds affect theperformance of the welding joints. In this paper, the joints of Magnesium andAluminum alloys are joined by AC MIG and AC TIG welding, using Zinc as theintermediate layer.AZ31B Magnesium alloys and6061Aluminum alloys of the1mm thicknessare used as the study objects, using Zinc of the0.2mm thickness as the intermediatelayer, by MIG welding separately using the pure Aluminum, AlSi₅, AlSi₁₂andER5356wire. The results show that much Al₃Mg₂exists in the welding center, andAl₁₂Mg₁₇exists in the Magnesium interface. MgZn₂and Mga2Si are founded in thewelding joint, which improves the performance of the welding joints. When toomuch Si is molten into the welding center, the account of the pore increases. Whenthe welding heat input is42.0KJ/m by using the AlSi₅wire, the joint strengthreaches the highest63.010MPa. A large number of pore defects exist in the weldingjoints, which influences the properties of the welding joints.AZ31B Magnesium alloys and6061Aluminum alloys of the1mm thicknessware used as the study objects, using Zinc of the0.2mm thickness as theintermediate layer by TIG welding, the Aluminum plate above the Magnesium plate.The joining joints can get good performance. And using the compaction equipmentalong with the welding and B2O3surfactant, the properties of the welding joints areimproved. AZ31B Magnesium alloys and6061Aluminum alloys of the3mmthickness are welded, by separately using the Zinc of the thickness of0.2mm,0.4mm and0.6mm as the intermediate layer. With the thickness of the Zincincreasing, the account of Zn element and the MgZn₂in the welding center increase.When the thickness of the Zinc was0.4mm, the the joint strength is the highest.The microhardness of the magnesium interface is the highest and the fractureposition is in the Magnesium interface, where exists Al₁₂Mg₁₇. The fracturemechanism is brittle rupture.