Laser welding process and temperature field analysis of aluminum alloy thin-walled tube

A 7075 aluminum alloy round tube with a wall thickness of 0.7 mm is taken as the research object, and a combination of welding test and simulation method is adopted. The macroscopic topography, weld size, and microhardness were analyzed under different welding parameters. The workpiece temperature change and weldment deformation during welding are calculated in abaqus. The calculation results of the temperature field and the stress field are compared and analyzed. The research results indicate that laser power affects the heat input. As the laser power increases, the fusion zone gradually increases, the molten width increases, and even the workpiece is fractured at 480 W. The welding speed affects the energy absorption of the workpiece. As the speed decreases, the molten width and depth increase, and the workpiece transitions from an incomplete to a moderate fusion state. When the defocus amount is 1 mm, the welding effect is better. The temperature distribution cloud map showed an elliptical shape, with a dense distribution at the front end of the heat source and a sparse distribution at the back end. The heat-affected zone gradually diffused from the weld to both ends. By collecting nodes from various regions of the weld seam and analyzing their thermal cycle curves, it was discovered that the closer a node is to the center of the heat source, the higher its maximum temperature, and the more severe the temperature variation. The research in this paper provides a theoretical basis for applying aluminum alloy laser welding technology in the field of new energy vehicles and the manufacture of aircraft fuselage.