Effect of Ceramic Particles on Microstructure and Mechanical Properties of Aluminium Surface Composite Fabricated Using Friction Stir Processing

Friction stir processing (FSP) is a novel technique used to fabricate surface composites. This investigation is an attempt to made Al/Al₂O₃ and Al/SiC surface composite using FSP and compare the mechanical and metallurgical properties influenced by the types of reinforcement particles. Two plates were grooved with 0.8 mm in width, 5 mm in depth and 100 mm in length in the middle of the aluminium plate using wire EDM and compacted with Al₂O₃ and SiC powder. The FSP was carried out automatically on an indigenously built FSW machine at tool rotational speed of 1200 rpm, processing speed of 60 mm/min and axial force of 10 kN. The optical and Scanning Electron microstructures are precisely revealed the homogeneous distribution of Al₂O₃ and SiC particles in the stir zone of surface composite layer (SCL). The microhardness was measured across the cross section of SCL layers of Aluminium and Aluminium with SiC and Al₂O₃. The higher microhardness was obtained in Aluminium with SiC and Al₂O₃ composites fabricated by FSP. This is because of the higher hardness value of SiC particles than Al₂O₃ particles.