Enhanced Fatigue Properties of 2219 Al Alloy Joints via Bobbin Tool Friction Stir Welding

In the present study, 2219-T87 Al alloy plates, 4 mm in thickness, were subjected to bobbin tool friction stir welding (BT-FSW) under relatively high speeds of 200 and 400 mm/min, with aim analyze effect on fatigue properties joints. The results showed that tension–tension high-cycle performance BT-FSW joints at room temperature was significantly enhanced compared other 2xxx series alloys counterparts. Particularly a speed strength joint reached 78% base material together tensile 311 MPa. It found line remnants had no effects due elimination root flaws action lower shoulder. Most samples mm/min failed thermo-mechanical zone (TMAZ) during tests, attributable coarsened grains precipitates, but all randomly nugget improved hardness value TMAZ.