Tensile strength of double side friction stir welding using varied length of pin and rotating directions

This article discusses the Double Side Friction Stir Welding (DSFSW). The pin length and the rotation direction of the tool are varied to enhance the resulting tensile strength. The reverse DSFSW (DSFSW-R) is proven to provide a higher joint strength due to the mass transfer mechanism that occurs in the DSFSW process. The increase of the pin's length enlarges the interference zone that multiplies the effect of strain hardening. The strain hardening is severer in DSFSW-R, and the gap between data measured in the DSFSW-R case and the in-line Double Side Friction StirWelding (DSFSW-i) case is wider due to the effect induced by the use of a longer pin.