Dynamic thermo-mechanical phenomenon and multi-scale strengthening mechanism during friction stir weld-riveting process

点击翻译按钮获取中文摘要

An integrated one-step friction stir weld-riveting (FSWR) process combining friction stir spot welding (FSSW) and self-piercing riveting (SPR) is proposed to join 7 series aluminum alloys. Using inprocess friction heating and high-speed rivet stirring to ①prevent crack defect, achieve ②fine grain strengthening via dynamic recrystallization, and form a hybrid joint with ③solid-state bonding and④mechanical interlock. This research elucidates the control mechanisms of friction heat and rivet stirring on the above four key features. In addition, multi-scale strength evaluation models and miniature tensile tests were performed to clarify the hybrid strengthening mechanisms of the four key features on the overall mechanical performance of the FSWR joints.