Tribological Behavior of Hybrid AA6061/SiC/Carbonized Coconut Shell Nanocomposites

Abstract

In the present investigation, hybrid aluminum matrix composite was prepared by stir casting method using aluminum alloy 6061 as the matrix material and nanoparticles of carbonized coconut shell (CCS) and silicon carbide (SiC) as reinforcements, and characterized for wear behavior. The average reinforcement particle sizes were 42.3 nm and 50.01 nm for SiC and CCS respectively. The weight percentage of CCS and SiC nanoparticles were varied at equal amounts ranging from 3 to 15 wt.%, with 3 wt.%  steps. Wear test was done on a Pin on disc apparatus at varying load of 10 N, 20 N, 30 N, 40 N and 50 N under dry sliding conditions, at a constant speed of 2.0 m/s and a sliding distance of 400 mm. The wear loss and wear rate of each sample during the wear process was recorded by using a computer. The chemical composition and microstructural study of the composites were done using x-ray fluorescence (XRF) and scanning electron microscope (SEM), which revealed uniform distribution of nanoparticles of CCS (containing majorly SiO2, Al2O3 and Fe2O3) and SiC in the matrix alloy. The wear results revealed that both the volumetric wear loss and wear rate of the composites decreased with increased weight percent of reinforcement, but increased with increased load. The results also indicated that the coefficient of friction of the composites increased with increased weight percent of reinforcement, particle size and applied loads.