Successful joining of ultra-thin AA3003 aluminum alloy sheets by the novel GTAW process

Joining ultra-thin aluminum sheets with the current welding technologies is very challenging because of the difficulty in controlling the heat input and the defect formation (thermal deformation). In this paper, the butt weld of 0.08-mm-ultra-thin AA3003 aluminum sheets was successfully performed utilizing the novel GTAW technology and the DCEN polarity mode. The results show that the weld bead has a good appearance with full penetration and free of hot tears or crack defects. Tensile samples were all fractured at the junction zone between the base-metal zone (BMZ) and the heat-affected zone (HAZ), confirming that the weld metal zone (WMZ) has the highest strength. The novel GTAW process with the novel collet's efficiency permits removing and blowing away the oxidation layer on the workpiece surface. Therefore, the welded joint has high quality without porosity and crack defects. This capability is a unique feature of the developed GTAW process compared to current welding technologies. © 2022