LAUSR

Abstract The present study is to improve the damping properties of AA6061-T6 alloy by incorporating graphite (Gr) flakes through friction stir processing (FSP). The amount of graphite varied from 5 to 15 vol%. The distribution of graphite particles and the microstructure refinement were analysed using optical and electron microscopy. The grains were indistinguishable in the stirred zone. The hardness of the surface composites decreased with an increase of graphite fraction. The dynamic mechanical analyzer was used to analyze the damping capacity of specimens extracted from the stir zone. The frequency dependent and temperature dependent damping capacity of FSP-ed AA6061 and the surface composites were observed to be better than the base metal. Significantly, the damping capacity of composite with 15 vol% graphite was 3.5 times of base-metal's damping at 250 °C.