11. Joining by friction stir welding

Friction stir welding (FSW) exploits aluminium’s ability to withstand extreme plastic deformation at elevated temperatures without melting the work piece.

A rotating, non-consumable welding tool is plunged into the aluminium work piece to a pre-determined depth, generating heat through friction and plastic deformation. The rotating tool is traversed through the work piece along a defined path, creating a butt or lap weld over the trailing length of the tool path.

The simultaneous tool rotation and traverse transfers plasticized material around the tool to deposit material on the trailing side of the weld path. The process creates a defect-free, homogenous joint that requires little to no post-processing for surface appearance.