ABSTRACT
The friction stir welding process was developed in 1991 by The Welding Institute (TWI) for joining aluminum alloys (Thomas 1991) and subsequently the process has been used during joining of titanium, magnesium, zinc and copper alloys, and steel, in thicknesses ranging from 1 to 50 mm (Thomas, Threadgill, and Nicholas 1999; Nagasawa et al. 2000; Fukuda 2001; Cederqvist and Andrews 2004; Reynolds, Hood, and Tang 2005). The process involves plunging a rotating tool consisting of a cylindrical shoulder and protruding pin and traversing the tool across two pieces to be joined. Figure 8.1 shows a schematic of the friction stir welding process employed in producing a buttwelded section.
