Research on the Laser Automatic Welding Process Technology of the Sheet Metal Shell of 5052 Aluminum Alloy

The article takes laser welding of 2mm thick 5052 aluminum alloy sheet metal shell as the research object, and conducts process research from the aspects of weld seam structure improvement, adjustment of welding misalignment, and optimization of weld seam sequence. The microstructure and mechanical properties of the welded joint are analyzed. The research results indicate that when the misalignment of the shell welding is 1mm, the convex structure of the misalignment helps to attach the welding wire droplets, making the weld surface full and smooth. Optimizing the weld sequence can improve the lodging problem of the suspended butt weld structure. There is a fine equiaxed crystal structure at the fusion line and the center area of the welded joint, and the transition area from the fusion line to the center of the weld is composed of columnar crystals. Thanks to the stirring of the laser beam, the overall microstructure of the joint is refined. The hardness of each area in the welded joint is lower than that of the base metal, with an average tensile strength of 197.4 MPa, reaching 87.2% of the base metal. The elongation at break is about 5%, which is lower than the mechanical properties of the base metal. The softening effect of laser on the welded joint is significant.