Friction stir welding: after a decade of development

Friction Stir Welding (FSW) is an innovative solid state welding process invented in 1991 by TWI- The Welding Institute [1]. FSW can arguably be said to represent one of the most significant developments in joining technology over the last half century. The initial development by TWI and its industrial partners under various Group Sponsored Projects focused on single pass, complete joint penetration of arc weldable (5XXX and 6XXX) and un-weldable (2XXX and 7XXX) aluminum alloys up to I inch thick. By 1995, FSW had matured to a point where it could be transitioned and implemented in the US aerospace and automotive markets. The many advantages of FSW compared to conventional arc welding have repeatedly been demonstrated with both improved joint properties and performance. Often, production costs are significantly reduced. Other times, FSW enables new product forms to be produced or skilled labor freed to perform other tasks. Research and development efforts over the last decade have resulted in improvements in FSW, and, the spin-off of a series of related technologies.