Research on Microstructure and Mechanical Properties of CMT and MIG Welded Joints of A6N01 Aluminum Alloy

Abstract Cold metal transition welding (CMT) and molten inert gas shielded welding (MIG) two welding processes were used to conduct butt welding tests on 2mm thick 6N01 aluminum alloy, and the microstructure and mechanical properties of the welded joints obtained by the two processes were tested.The results show that the welded joints of 6N01 aluminum alloy welded by CMT process have better appearance and less welding defects and welding spatter. The tensile strength of CMT welded joints is 213MPa and the elongation after fracture is 10.64%, which is slightly higher than that of MIG welded joints. The hardness distribution of CMT and MIG welded joints and the hardness values of each zone are basically the same. Compared with MIG welded joints, the grain structure of CMT welded joints and the equiaxed crystals on the side of the fusion zone near the base metal are smaller and more uniform.