Friction Stir Welding 

FSWFriction Stir Welding is a joining process where the two pieces to be joined are heated and softened by friction with a rotating tool. The process requires the plates to be clamped. The rotating tool is inserted into the joint line to produce a solid-state weld by mechanically mixing the plasticised/softened materials. The tool then follows the joint line to produce butt or lap joints. 

As the pieces are not melted, this technique avoids many of the defects associated with fusion welding, such as solidification cracking and porosity. It is used to produce high-quality, high-strength welds with low distortion in aluminium and other materials. FSW is widely used within the transport manufacturing industry. 

The technique was invented by TWI as recently as 1991.

For more information on FSW see:

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