Optimal FSW process parameters for interface and welded zone toughness of dissimilar aluminium–steel joint

Abstract The main purpose of this paper is to determine the optimum operating conditions of friction stir welding dissimilar metals joints, namely AA6061 aluminium alloy and SS400 low carbon steel. The optimum operation is the combination of four mainly controllable process parameters for the best quality of uncontrollable parameters, such as both interface and welded zone impact values. In this paper, the V-notch impact value represents the interface toughness and the C-notch impact value for welded zone toughness. Moreover, the possible failure type can be analysed by observing the fractured surface after impact test. The best bending toughness of dissimilar metals joints is produced by the combination of the tool rotation speed of 550 rev min–1, the transverse speed of 0·9 mm s–1, the tool tilting backward 2° angles, and the tool pin diameter of 6 mm.