Mechanical analysis of ultra-thin friction stir welding joined sheets with dissimilar and similar materials

In the last ten years, aerospace and automotive industries have addressed large attention to a new welding technology based on a solid-state process, called friction stir welding (FSW). FSW process shows several advantages, in particular the possibility to weld dissimilar aluminium alloys. In this paper, thin aluminium alloy 2024-T3 and 6082-T6 sheets, 0.8 mm thick, have been welded in the rolling direction by μFSW (FSW for ultra-thin sheets). Both similar and dissimilar joints have been successfully produced and analysed. Mechanical characterization has been executed through static and uniaxial fatigue tests with a constant load amplitude. Finally, microhardness and residual stress measurements have been executed on welded sheets for each joint typology.