Analysis of Residual Stress on Dissimilar Butt Joint by TIG Assisted Hybrid Friction Stir Welding

Abstract This paper aimed to study and understand the mechanical phenomena of thermal elasto-plastic behavior on the dissimilar butt joint (Al 6061-T6 and STS304) by TIG assisted Friction Stir Welding. Heat conduction and residual stress analysis is carried out using in-house solver. Two-dimensional results of the heat distribution and residual stresses in dissimilar joint for particular tool geometry and material properties are presented. The predicted stress along longitudinal direction in Al 6061-T6 and STS304 are approximately between 12-15% of their respective yield strengths. A comparison is made between experimentally measured and numerically predicted equivalent residual stress values.Key Words : Friction stir welding, Dissimilar material, Heat conduction, Residual stress, strain gauge 1. Introduction A reliable method to join dissimilar materials would make it possible to make these joints in several applications such as in automobiles, aerospace, shipbuilding and so on. Friction stir welding (FSW) patented by W. Thomas and his colleagues of The Welding Institute (TWI), UK, in 1991 is an innovative joining process which can weld dissimilar alloys traditionally considered unweldable