Friction stir welding (FSW) is a well-established technology for joining aluminium alloys. The majority of industrial applications involve joining components in a thickness range of 2–10mm, but advances in FSW tooling and techniques are now extending this range.
Joining sheets less than 1mm thick becomes increasingly challenging using conventional FSW. However, stationary shoulder FSW has shown some impressive results, joining materials as thin as 0.3mm with minimal weld undercut and a smooth external surface.