A Weldment Characteristics on Laser Welding of 2XXX Aluminum Alloys

Abstract

In the aerospace industry, high-strength heat-treated aluminum alloys are increasingly being used for large wing structures, which are typically designed by welding thin skins to a pocketed frame structure to reduce weight. Owing to the limited welding area between the frame and the skin and the limited space in the chamber, laser welding is the most suitable manufacturing process. Therefore, the weld-ability and the strength of laser-welded aluminum frame-skin structure must be determined. In this study, AA2219 of the A2XXX alloy series was tested under various welding conditions. Analysis of the bead shape in the cross-section of the welded frame?skin revealed that the optimal welding conditions can be achieved when the ratio of the bead width to penetration (L/H) is minimal. The weld-ability of AA2219 was compared to that of AA2024 by examining the 1) spatter and porosity, 2) hardness in the heat-affected zone, and 3) tensile strength of the two alloys welded under the determined optimal welding conditions. The tensile strength of laser-welded AA2219 and AA2024 was 79% and 70% of that of the base material, respectively. Because the tensile strength value of the welded AA2219 was nearly equal to the yield strength value of the base material, the AA2219 laser-beam welding process can be applied to large wing structures.