Friction Stir Welding of Dissimilar Metals: Advancements, Challenges, and Applications in Industrial Manufacturing

Abstract

Friction Stir Welding (FSW), a solid-state joining process, has emerged as a transformative method for the welding of dissimilar metals, particularly for combinations that are difficult to join using conventional fusion welding techniques. The ability of FSW to produce defect-free joints with superior mechanical properties makes it an attractive solution in sectors such as aerospace, automotive, and marine industries. This paper provides a comprehensive overview of FSW applied to dissimilar metal joints, focusing on material compatibility, microstructural evolution, tool design, and process optimization. Challenges such as formation of intermetallic compounds, tool wear, and residual stresses are critically discussed. The study also includes a statistical and experimental review of recent developments in Pakistan, demonstrating the national research contribution in this field. Two graphical analyses highlight the mechanical performance and defect trends associated with key dissimilar metal pairs.