Dry sliding wear behaviour of ultrasonically-processed AA6061/SiCp nanocomposites
DOI:
https://doi.org/10.15282/ijame.14.4.2017.12.0373Keywords:
AA6061; dry sliding; sliding velocity; wear loss; coefficient of friction; worn surface examination.Abstract
The present study focused on the wear performance of AA6061/ SiCp (1, 1.5 and 2 wt. %) of nanocomposites at dry sliding condition. The nanocomposite specimens were fabricated through ultrasonic assisted stir casting technique. The wear experiments were
conducted under normal atmospheric conditions using a pin-on-disc apparatus. Three different applied normal loads on nanocomposite pin (10 N, 15 N, and 20 N); at various sliding velocities of (1 m/s, 1.5 m/s, and 2 m/s); and at sliding distances of (1000 m, 2000 m, and 3000 m) were considered. The influences of applied normal load on nanocomposite pin, wt. % of SiCp reinforcement particles, sliding velocity, and sliding distance on both friction coefficient and wear loss were studied. The changes of wear loss
and friction coefficient with varying applied normal loads, sliding velocities, and sliding distances were plotted. It was observed that the wear loss increased linearly with increasing sliding distance and sliding velocity. This was due to the increase of oxidation
layer on the pin surface. The average friction coefficient at sliding velocity 1 m/s for 1 wt. % of SiCp, 1.5 wt. % of SiCp, and 2 wt. % of SiCp reinforced nanocomposites at sliding distance 3000 m, at 20 N normal loads was 0.29, 0.43, and 0.46, respectively. The
average friction coefficient at 2 m/s sliding velocity for the same load and sliding distance was 0.26, 0.27, and 0.28, respectively. The increase of SiCp reinforcement in the matrix increased the friction coefficient due to its cubic crystal structure. The increase of sliding
velocity and sliding distances reduced the friction coefficient. The worn surfaces of the samples were examined using SEM and EDX analyses. SEM micrograph analysis of the wear surfaces of the nanocomposites exhibited the abrasion wear and oxidative wear with
severe plastic deformation. The shallower scratches, circular grooves, and deeper grooves were identified at different conditions on the worn surfaces.
