Ageing behavior of aluminum hybrid metal matrix composites

Astir casting processwas used to fabricate aluminumcomposites reinforced with various volume fractions of 2, 4, 6, and 8 wt%rice husk ash (RHA) and silicon carbide (SiC) particulates in equal proportions. The study was undertaken to investigate the ageing response of the aluminum alloy (A356.2) when dispersed with RHA and SiC particles. A systematic study of the base alloy and composites was done using the Brinell hardness measurement and the corresponding age hardening curves were obtained. It was observed that in comparison to the base aluminum alloy, the precipitation kinetic was accelerated by adding the reinforcement. This effect reduced the time for obtaining the maximum hardness by the aging heat treatment.