The Friction Stir Welding (FSW) process is purely mechanical, clean, environmentally friendly and capable to make weld lines of the highest quality. Other benefits are the ability to join certain dissimilar metallic materials and some aluminium alloys, which are difficult to weld by conventional fusion methods. The FSW process can use existing and readily available machine tool technology and the process is suitable for automation and now also adaptable for robot use. The relatively low residual stresses and the fine-grained, stirred zone result in very good strength properties together with good ductility, characteristics particularly important in aerospace applications. The pieces to be welded need only little surface preparation and the process can, to a certain extent, accept gaps and mis-alignment. This is a major advantage compared to fusion welding, where a special surface preparation is required. Welding filler metals or an inert gas are not necessary either. The FSW process creates very low noise levels and does not emit smoke, dust, dangerous plasma or x-rays |
