Development of Friction Stir Clinching Process for Alclad 2024-T3 Aluminum Sheets 2016-01-0505

A concept of combining friction stir spot welding (FSSW) and clinching, denoted as friction stir clinching (FSC), was proposed to join alclad 2024-T3 aluminum sheets. A tool, having a smooth probe and a flat shoulder, and a die, having a circular cavity and a round groove, were used to make FSC joints. The failure loads and fatigue lives of FSC joints made by various punching depths, rotational speeds, and dwelling times, were evaluated to obtain the admissible processing parameters. Optical micrographs of the FSC joints, before and after failure, were examined to understand the effects of processing parameters on the mechanical interlock and alclad layer distribution, which strongly correlate to the failure load, failure mode, and fatigue life of FSC joints. Finally, the static and fatigue performance of FSC joints made by the admissible processing parameters was obtained. The feasibility of the FSC process for alclad 2024-T3 aluminum sheets was confirmed.