Simulated Annealing Based Parameter Optimization for Friction Stir Welding of Dissimilar Aluminum Alloys

Friction Stir Welding (FSW) is one of the latest solid state joining techniques being extensively used for joining many similar and dissimilar material combinations for structurally demanding applications and the results are promising. The weld qualities of the FSW joints depend on the process parameters used. Aluminum alloys AA2024 and AA7075 find applications in aircraft industries and pose challenges when joined using conventional fusion welding techniques. In this study, friction stir welding of dissimilar aluminum alloys AA2024-AA7075 is performed at different tool rotation speeds (TRS) and welding speeds (WS) as per central composite design with three factors and three-levels for each factor (face centred). Response surface methodology is used a mathematical model for predicting the tensile strength of the resulting joints was developed. The model is used to study the effect of the TRS and WS on the strength of the joints. The tensile strength of the joints is found to be affected by both the TRS and WS. Simulated Annealing is used to optimize the TRS and WS for maximizing the tensile strength of the joints. Optimum values of the TRS and WS are found to be 1087.6 rpm and 14.12 mm/min respectively. The maximum tensile strength of the joints is predicted to be 271.084 MPa when these parameters are used.