Friction Stir Welding (FSW) was invented by Wayne Thomas at TWI Ltd in 1991 and overcomes many of the problems associated with traditional joining techniques. FSW is a solid state process which produces welds of high quality in difficult to weld materials such as aluminium and is fast becoming the process of choice for manufacturing light weight transport structures such as boats, trains and aeroplanes. See more:
http://en.wikipedia.org/wiki/Friction_stir_welding