Process force reduction in friction stir spot welded EN AW 1070/C1020R for thin sheet applications
By Tobias Koehler (Technische Universität Ilmenau), Michael Graetzel (Technische Universität Ilmenau), Jean Pierre Bergmann (Technische Universität Ilmenau), Aristide Tchouaha Tankoua (Daimler AG), Philip Betz (Daimler AG)

Against the background of energy efficiency and electromobility, approaches for lightweight design and for short cycle times as well as cost reduction in the field of current-carrying components, have made the joining of aluminum and copper in focus of a lot of researches. In this work, a dissimilar 1 mm EN AW 1070 and a 0.7 mm C1020R lap joint was connected by an innovative force-controlled friction stir spot welding setup (FSSW). An approach for force reduction via tool scaling is shown. This enables process times below 0.5 s and constant mechanical properties of the weld seam, which is due to the generation of a local melt formation with a eutectic composition at the interface.