Microstructure and Mechanical Properties of the Aluminium Alloy 6056 Welded by Friction Stir Welding Techniques

Results of a comparative study carried by conventional and bobbin-tool Friction Stir Welding (FSW) technologies are presented. Aluminium sheets of AA6056 (Al-Mg-Si-Cu alloy), were welded by the standard FSW and bobbin tool techniques. Mechanical and microstructural characteristics were determined for three different thermal treatments, T4, T6, and T78, in two starting conditions of the material, namely as-welded and post-welded. The analysis of results is based on the influence of the welding technology as well as the initial temper selected prior to welding on the residual performances of the weld. The study is mostly focused on T78 tempers.