A Modified Friction Stir Welding Process Based on Vortex Material Flow

Abstract Friction stir welding is a promising solid-state welding technique. However, the issue of tool wear and break restricts its wider industrial application. To avoid the tool wear and break occurring in conventional friction stir welding (FSW), a new modification of the FSW process using a tool made by the identical material as the workpiece has been developed and conducted on pure aluminum. We named this process as Vortex-FSW (VFSW) because it depends on a vortex material flow to realize the welding and joining. The weld macro- and micro-structures are like that in conventional FSW. However, the tool exit-hole in conventional FSW is replaced by a lug boss. The mechanical properties are also equivalent to that in conventional FSW. The principle of this new process is introduced in this paper.