Damping Behavior of $Al-Li-SiC_p$ Composites Processed by Stir Casting Technique

Abstract

Damping characteristics of 8090 Al alloy and its composites reinforced with 8, 12, and 18 vol pct SiC particles were investigated using a dynamic mechanical analyzer (DMA). Tests were done at different frequencies over a temperature range of $27^oC$ to $300^oC$. Composites show higher damping capacity than the unreinforced alloy. Damping capacity is found to increase with decreasing frequency. An equation relating damping capacity with frequency has been proposed. The damping data are analyzed in the light of matrix microstructure and different operative mechanisms