Effect of T6 heat treatment on damping characteristics of Al/RHA composites

In the present work, effect of T6 heat treatment on the damping behaviour of aluminum/rice husk ash (RHA) composites fabricated by vortex method was studied using dynamic mechanical analyser (DMA) at frequencies ranging from 1 Hz to 25 Hz at room temperature under three-point bending test mode. The matrix material for the present work was A356·2 and reinforced with different weight % of 4, 6 and 8 rice husk ash particles. It was observed that composite exhibits high damping capacities than unreinforced alloy and increases with increase in weight % and the storage modulus increases with the addition of RHA particles but decreases with the increase in weight %. The heat treated composites exhibit higher damping capacity than the composites without heat treatment and increases with the increase in weight % of the reinforcement and loss in the storage modulus was observed and further decreases with the increase in the weight % of reinforcement. The related mechanisms were also discussed.