Effect of Reinforcement Particle Size on the Properties of Dispersion Strengthened Al-SiC Composite

The effect of reinforcement silicon carbide particle size on Al-20vol% SiC composite fabricated via powder metallurgy route has been investigated. Composite powders consist of alumina and silicon carbide of different particle sizes (i.e. 3.7µm, 12.5µm, 17.5µm and 50µm) were mixed for 2 1/2 hours in a tumbler mill. Compacts were obtained by cold pressing the composite powder at 200 MPa and sintering in argon atmosphere at 600°C for 5 hours. Results showed that size of silicon carbide powder has a considerable effect on the composite properties. As a conclusion, the use of finer silicon carbide powder has increase the density, hardness, modulus of rupture and electrical resistivity of the composite.