Characterization of mechanical properties of aluminium/tungsten carbide composites

This study deals with the investigation on mechanical properties of aluminium alloy (AA 6082) composites reinforced with tungsten carbide particles. Stir casting process was employed to fabricate the aluminium composite specimen by varying tungsten carbide in 2, 4, 6, 8 and 10% by weight. The composites were exposed to density, hardness, tensile and impact studies. Scanning electron microscope was used to investigate the mechanism of the fractured tensile and impact test specimen. The density, impact strength and elongation of the composites decreased with increase in addition of tungsten carbide, while the hardness of composites increased with increase in tungsten carbide. The tensile strength of the composites increased initially and then tends to decrease. Fracture of the composites is characterized by dimples, voids, cracks, ridges, pits and particle fracture. Brittle fracture of composites in the form of cracks and particle fracture are due to the strong interfacial bonding between the tungsten carbide and aluminium matrix at high strain rate. High impact strength of composites are due to ductile failure in the form of dimples, while low impact strength are due to brittle and plastic deformation characterized by micro and macro cracks, particle fracture.