Effect of Fly Ash and SiC Particles on Hardness and Microstructure of Friction Stir Welded MMCs

Metal matrix composites (MMCs) constitute an important class of design and weight efficient structural materials that are encouraging every sphere of engineering applications. Since, there has been an increasing interest in composites containing low density and low cost reinforcements. In the present work, Friction Stir Welding (FSW) has been used to join the AA6061 reinforced with SiC and Fly-Ash hybrid metal matrix composites (MMCs). Accordingly, rectangular composite plates were fabricated through stir casting route, then these plates were welded by using FSW. Micro-structural characterization of the stir zone was carried out through Optical Microscopy (OM). The uniform grain distribution was observed across the stir zone of AA6061/SiC/Fly-Ash composites after FSW. In addition, the evaluation of hardness was carried out and observed that a considerable increase in the hardness in the weld nugget zone when compared to the base metal for all percentage composition of fly Ash particles across the stir zone resulting successful method for FSW of AA6061/SiC/Fly-Ash composites has been developed.