What is Friction Stir Welding and what are its advantages?

Friction Stir Welding (FSW) is a solid-state joining process where a rotating tool with a pin and shoulder plunges into the joint and traverses along, generating frictional heat to plasticize and join materials without melting. Advantages: Excellent joint properties (often stronger than parent material), No filler metal required, Low distortion and residual stresses, Suitable for difficult-to-weld aluminum alloys (2xxx, 7xxx series), Environmentally friendly (no fumes/spatter), and Good for long welds. Widely used in aerospace (aircraft fuselages), automotive (aluminum structures), and shipbuilding.