Friction Stir Welding (FSW), invented at TWI in 1991, is a solid state process which produces high integrity joints in hard to weld materials such as aluminium, copper and in recent developments even in materials like titanium, stainless steel and mild steel.
Due to the fact that the process take place in the solid phase, results that is possible to weld materials that are difficult to fusion weld, like 2XXX and 7XXX aluminium alloys, magnesium and copper or to weld different kind of materials, like aluminium and copper, steel and aluminium, and so on.
Due to the high strength of the joint produced with this technique, this technology leads to be an outsmarting choice for manufacturing lightweight boats, trains, aeroplanes and all the structures where high strength, low weight, good toughness and excellent fatigue life are required.
The process is also suitable for automation, and has no one of the common hazards coming from the usual welding techniques, so there is no fumes emission, no hazardous radiation, low energy consumption and no filler material required.
The main advantages are low distortion and shrinkage, excellent mechanical properties, no porosity, no spatter, energy efficient, no gas shielding, all characteristics of an eco-friendly and hazard free process.
Another still uninvoiced advantage is the fact that FSW can repair cracked base material or faulty MIG joints, re establishing or increasing joints structural integrity.