Friction Stir Welding

Abstract

This chapter deals with the various aspects of joining dissimilar materials using the friction stir welding (FSW) technique. The joining of dissimilar materials is an important need for the manufacturing sector, especially the automobile industry. It helps in the weight reduction of the vehicle, which in turn reduces fuel consumption. Therefore, dissimilar weld joints are important from both an economical and sustainable point of view. FSW develops the joint below the melting point of the base metal, thus significantly reducing the chance of intermetallic formation, especially in the case of dissimilar friction stir-welded joints. FSW is widely used for the joining of aluminum alloys. The automobile industry commonly uses the dissimilar joint of aluminum alloys with other metal systems, like steel, to achieve a high strength-to-weight ratio. In view of this, the characteristics of FSW joints of dissimilar aluminum alloys, aluminum to other metal systems, and dissimilar metal systems other than aluminum, as well as major issues with the dissimilar FSW joints, are discussed. The metallurgical, mechanical, and electrochemical behaviors of the dissimilar FSW joints are discussed and correlated with the change in microstructure.