The effects of various reinforcements on dry sliding wear behaviour of AA 6061 nanocomposites

The present work aims to investigate the dry sliding wear behaviour of AA 6061 nanocomposites reinforced with various nanolevel reinforcements, such as titanium carbide (TiC), gamma phase alumina (γ-Al2O3) and hybrid (TiC+Al2O3) nanoparticles with two weight percentages (wt.%) prepared by 30h of mechanical alloying (MA). The tests were performed using a pin-on-disk wear tester by sliding these pin specimens at sliding speeds of 0.6, 0.9 and 1.2m/s against an oil-hardened non-shrinking (OHNS) steel disk at room temperature. Wear tests were conducted for normal loads of 5, 7 and 10N at different sliding speeds at room temperature. The variations of the friction coefficient and the wear rate with the sliding distances (500m, 1000m and 1600m) for different normal loads and sliding velocities were plotted and investigated. To observe the wear characteristics and to investigate the wear mechanism, the morphologies of the worn surfaces were analysed using a scanning electron microscope (SEM). The formation of an oxide layer on the worn surface was examined by energy dispersive spectroscopy (EDS). The wear rate was found to increase with the load and sliding velocity for all prepared nanocomposites. Hybrid (TiC+Al2O3) reinforced AA 6061 nanocomposites had lower wear rates and friction coefficients compared with TiC and Al2O3 reinforced AA 6061 nanocomposites.