Investigation of the Microstructure and Mechanical Properties in Friction Stir Welded Dissimilar Aluminium Alloy Joints via Sampling Direction

This research study investigates the influence of sampling direction on microstructure and mechanical properties dissimilar joints formed by friction stir welding (FSW). The specimens were cut in two directions: perpendicular (transverse) parallel (longitudinal) to FSW joint. tests conducted included X-ray diffraction (XRD), macrostructure, microstructure, tensile, microhardness, fractography analysis. Different phases noted XRD patterns explained, with aluminum phase being dominating one. results further showed that transverse joint exhibited higher microhardness compared longitudinal joint, which is consistent respective grain sizes. Moreover, ultimate tensile strength exceeded joints, showing a substantial 47% increase. Similarly, elongation followed similar trend, displaying significant 41% increase Fractographic analysis revealed ductile fracture behaviour all joints.