Development of in situ MMC joint using friction stir spot welding of Al6061-T6

In this study, friction stir spot welded joints of Al6061-T6 were obtained using silicon carbide particles as reinforcement. The effect of reinforced particles along with process parameters was analyzed in terms of tensile-shear strength, weld structure, and hook formation. The investigations revealed that tensile-shear strength increased by 29.78% with incorporation of silicon carbide particles in the weld region. The guiding hole diameter was found to be a significant parameter for improved weld strength. Optimal levels of tool rotation speed, pre-dwelling time, and guiding hole diameter were observed as effective process parameters for better weld quality. Weld cross sections were studied under a stereo zoom microscope and an optical microscope to observe different bonding regions. The scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) confirmed the presence of silicon carbide particles in the weld region.