New Approaches to the Friction Stir Welding of Aluminum Alloys

Friction stir welding (FSW) is a technique able to guarantee welding advantages such as the easy control of tool design, rotation speed, and translation speed. This is also a reason for a continuous research activity to optimize the effect of the different welding parameters and tool-metal setups. In this contribution, two innovative welding methodologies are presented and discussed. A first new FSW configuration was defined as double-side friction stir welding (DS-FSW). In the DS-FSW, the welding is performed on both sheet surfaces, that is, the first welding is followed by a second one performed on the opposite sheet surface. In this chapter, the effect of the welding parameters, tool configuration and sheet positioning on the yield, ultimate strength, and ductility of an aluminum plate, its microstructure and its post-welding formability are discussed. A second new FSW configuration consists of a pin rotation around its centerline welding direction by 0.5 and 1.0 mm. This was defined by authors as RTtype configuration and it is characterized by a welding motion of the pin tool obtained by the combination of two different movements occurring simultaneously.