Influence of Varying SiO2 % on the Mechanical Properties of Al Based MMC

The current investigation is focused on effective utilization of rice husk ash (RHA) SiO2-an industrial waste available in abundance, by systematically dispersing into an Al-Mg (0.5, 1.0, 2.5, and 5.0 % by weight) matrix resulting in synthesis of composites via Liquid Metallurgy route. The effect of increasing Mg % to improve the wettability with the increase in SiO2 % as reinforcement was studied comparatively. The increase in the percentage of SiO2 beyond 5 % as reinforcement into Al-Mg alloy increases the agglomeration of SiO2 particles which creates more sites for crack initiation and hence lowers down the load bearing capacity of the composite while microhardenss and wear testing analysis. For the composite, Al-Mg (2.5 %)-SiO2 (5.0 %) the hardness was observed to be maximum corresponding to minimum wear loss. The uniform distribution of maximum amount of hard spinel structure of extremely small size within the matrix confirms maximum wetting characteristic of 2.5 wt% Mg.