Research On TIG-MIG Hybrid Welding Process Of Aluminum Alloy

Aluminum alloys play an important role in lightweight structural materials for their excellent physical and chemical properties,and their applications in aerospace,rail transportation,ship transportation and other fields are becoming more and more widespread.TIG-MIG hybrid welding combines the advantages of both TIG welding and MIG welding.Applying TIG-MIG hybrid welding to the welding of aluminum alloys can achieve high-efficiency welding of aluminum alloys and obtain high-quality aluminum alloy joints,which can further promote the application of aluminum alloys in industrial manufacture and national life.In this paper,the TIG-MIG hybrid welding bead weld was carried out with 6mm thick6061 aluminum alloy plates as the research object,and the influence of welding parameters on the weld formation was studied;The microstructure and mechanical properties of MIG welding joint and TIG-MIG hybrid welding joint were compared;The differences in microstructure and mechanical properties of ER5356 and ER4043 welding wires on5083/6061 dissimilar aluminum joints welded by TIG-MIG hybrid welding were compared;The heat source models of TIG-MIG hybrid welding and TIG-MIG hybrid welding with additional TIG arc were established for temperature field simulation test.MIG welding joint and TIG-MIG hybrid welding joint are compared.The weld microstructure of the two joints are dendritic crystals;the hardness,tensile strength and shear strength of TIG-MIG hybrid welding joint are superior to MIG welding joint.When the welding speed is 850 mm/min,the tensile strength of TIG-MIG hybrid welding joint is 246.5MPa and the elongation is 5.9%,the fracture mode is mainly ductile fracture;According to the metallographic diagram and hardness curve,the width of the fusion zone and the width of the heat affected zone of the MIG welding joint are both wider than those of TIG-MIG hybrid welding joint.The dissimilar aluminum alloy joints obtained by ER5356 and ER4043 welding wires were compared.The results show that the weld formation of ER5356 joint is better than ER4043 joint,but the tensile strength,elongation and hardness are not as good as the ER4043 joint;The tensile strength and elongation of ER4043 joint are 213 MPa and 8.88 %respectively.TIG-MIG hybrid welding temperature field simulation test shows that the dimensional error between the simulated weld and the actual weld is controlled within a reasonable range.The effects of MIG-TIG spacing and additional TIG current on molten pool morphology of TIG-MIG hybrid welding with TIG additional arc were explored.