Characterization of Friction Stir Processed Al6061/SiC Composite Made by Using Different Tool Pin Geometry

This research aims to study the effect of different tool pin shapes on the mechanical properties of friction stir processed (FSP) surface composites. The focus is on fabricating 6061-T6 Al/SiC composites using cylindrical, triangular, tapered cylinder, square, and hexagonal tool pin geometries. The experiments were conducted on a vertical milling machine with H13 tool steel at a transverse speed of 20 mm/min and a rotational speed of 1000 rpm, with three passes. Dye penetrant tests confirmed the absence of surface defects. Microhardness testing using the Vickers method showed that the square pin geometry achieved the maximum hardness value (120 HV). Surface topography analysis using optical and scanning electron microscopy revealed significant grain refinement and fragmentation of silicon carbide particles. Wear tests using a pin-on-disk tribometer indicated that 6061-T6 aluminum alloy without reinforcement exhibited the highest wear rate, while the square tool pin geometry resulted in the least wear rate due to increased microhardness. The processed Al/SiC composites demonstrated a lower average friction coefficient compared to the base metal.