The Effect of Particle size on Properties of Al-Si/SiO2 Particulate Composites

Abstract

Metal Matrix Composites (MMC) are relatively new class of engineering materials that possess high stiffness–to–weight ratio, significant weight reduction, wear resistance and thermal stability when compared with unreinforced matrix alloy. Extensive research work has been done on Alumina reinforcement in metal matrix. However, very little information is available in the literature on Al-Si/SiO2 particulate composites Stir-casting method of producing composites is particularly attractive to the developing nations venturing into MMPC development because of the reduced sophistication, possibility of using conventional foundry equipment and relatively low cost of the process. In this work, Stir-casting method was used to synthesise Al-Si/SiO2 Particulate Composites using silica reinforcement of different particle size. A 17% increase in strength was attained in composite reinforced with 10wt% coarse silica particles when compared with unreinforced alloy. The use of fine SiO2 particles equally improves the strength of Al-Si/ SiO2 composite. Higher degree of strengthening was achieved with the use of fine particles than with the use of coarse reinforcement particles.