Dependence of ultimate tensile strength of friction stir welded AA2024-T6 aluminium alloy on friction stir welding process parameters

Abstract

The aluminium alloy AA2024-T6 (Al–Cu alloy) has been widely used in the fabrication of high strength structures and in aircraft industries requiring a high strength-to-weight ratio and good ductility. Normally fusion welding processes are not suitable for welding of 2xxx and 7xxx series aluminium alloys due to their poor weldability. On the other hand Friction Stir Welding (FSW) process is an emerging solid joining process espe-cially suitable for joining of such alloys. The welding pa-rameters such as tool rotational speed, welding speed, tool pin diameter, axial force and tool pin profile significantly influence the mechanical properties of the FS welded joint. Mathematical model to predict the ultimate tensile strength (UTS) of the friction stir welded AA2024-T6 aluminium alloy were developed. Box-Behnken design was used to conduct the experiments and response surface method (RSM) was employed to develop the model. The devel-oped model was validated using the statistical tool analysis of variance (ANOVA). The interaction effects of the above process parameters on tensile behaviour of the friction welded joints are discussed in detail.