On the Residual Stress Field in the Aluminium Alloy FSW Joints

In this work, we evaluate the residual stress field originated by a new welding process named Friction Stir Welding. We analysed aluminium alloy butt-welded joints. Both similar and dissimilar joints have been considered in 2024-T3 and 6082-T6 aluminium alloy 0.8 and 3 mm thick. For each joint, the longitudinal and transversal residual stress distribution have been obtained in a direction normal to the weld cord. In the thicker dissimilar joints, the longitudinal residual stress distribution is very similar to the distribution present in the traditional welded joints. It presents, in fact, a tensile region near the weld cord, which is balanced by compressive regions away. On the contrary, other joints present a low compressive stress at the weld toe, which began tensile away. Moreover, the effect of the shoulder geometry on the residual stress field was evaluated on 1.5 mm thick joints