Swept Friction Stir Spot Weling (Swept-FSSW)

Schematics of (a) the side view and (b) the top view of the swept friction stir spot welding process.

The swept friction stir spot welding process is rather complex and can be divided into two portions. In the first portion, the rotating tool is indented into the sheets for a specific depth. In the second portion, the tool is moved outward for a distance and then swept counterclockwise along a circular path to stir more materials during the process. Finally, the tool is moved backward to the initial location and a swept friction stir spot weld is made. In general, the mechanical performance of the swept friction stir spot weld is better than that of the “traditional” friction stir spot weld mainly due to a larger stir zone.