Effect of CMT+P Welding Current on Microstructure and Mechanical Properties of 5083 Aluminum Alloy Welded Joints

CMT+P welding tests are carried out on 3 mm thick 5083-H116 aluminum alloy sheet at different welding currents, and the microstructure, tensile properties and bending properties of the joints are analyzed. The results show that the welding current has a significant effect on the mechanical properties of the joint and the grain size of weld center. When the welding current increases, the tensile strength decreases and the grain size of weld center increases. The welding joint that meets the using requirements can be obtained by adjusting the welding parameters of CMT+P. In this work, the optimal tensile strength, yield strength and elongation are 281 MPa, 163 MP and 67.92%, respectively, which are 84.38%, 13.5% and 75% of those of the base metal, respectively. The center of the weld is isometric crystal, and the inner side of the fusion line is columnar crystal.