Present work aims to achieve high welding speed during friction stir welding of lightweight battery trays in the electric vehicle industry. This study reports high-speed friction stir welding (HSFSW) up to 4.0 m mi -1 in AA6063-T6 alloys. The defect-free HSFSW joints are produced by adopting aggressive material mixing, i.e. higher tool rotation and plunge force. HSFSW weld cross-section reported an unusual hardness profile of "U"shape instead of "W"shape in conventional FSW of AA6xxx alloys. HSFSW resulted softening of weld stir zone (~60HV) along with HAZ (~53HV) against the base material (BM) hardness of ~90HV. The HSFSW at 4.0 m min -1 obtained good joint strength of 71% of the BM. Microstructure evolutions across the fractured weld cross-section are discussed using EBSD analysis.
The authors acknowledge the funding support from the Swedish funding body VINNOVA under the project of EVASTIR (2019-03114) and industry partners Volvo Car Corporation, Hydro Extruded Solutions, and ESAB.