Effect of nickel electroplating on the mechanical damping and storage modulus of metal matrix composites

The mechanical damping and the storage modulus of the nickel electroplated metal matrix composites have been studied using dynamic mechanical analyzer at different frequencies (0.1, 1 and 10 Hz) over a continuous heating temperature from room temperature to 150 degrees C. The rice husk ash (RHA) reinforced composites were fabricated using stir casting route. The nickel (Ni) plating was deposited on the base alloy and the MMC's using electroplating technique. The nickel plating is characterized using SEM. The results showed that damping performance of the base alloy and their composites was significantly improved by nickel plating. Also, nickel plated composites demonstrate higher damping values than that of the unreinforced and Ni plated base alloy. The mechanical damping for all the samples is frequency dependent over the whole temperature range. The storage modulus found to decrease with increasing temperature. The related mechanisms are explained and presented.