The Friction Stir Spot-Welding tool consists of a compression sleeve, a stir sleeve and a stir pin. The welding process includes the insertion of the compression sleeve, the extraction of the stir pin, the extraction of the compression sleeve and the backfilling of the stir pin, and then a solder joint to obtain a flat surface. By precisely controlling the relative movement of the components of the FSSW tool, the keyhole formed during the welding process is filled while the stir pin is withdrawn. Compared to the Resistance Spot Welding, the strength, shear resistance and fatigue resistance of FSSW welding spots are superior.
