Friction Stir Welding - Process Developments and Variant Techniques

Friction stir welding (FSW) is now extensively used in aluminium industries for joining and material processing applications. The (FSW) technology has gained increasing interest and importance since its invention at TWI almost 14 years ago. The basic principle and the continuing development of the FSW technology are described and recent applications are reviewed. The paper will introduce some of the variants of FSW, such as Twin-stir™ Skew-stir™, Re-stir™, Dual-rotation stir and the Pro-stir™ near-net shape processing technique. Particular attention will also be paid to tool probe/shoulder features, in relation to the joint geometry being welded. In addition, this paper makes special reference to the mechanical and structural integrity that can be expected from FSW technology.