Dry sliding wear behaviour of AA6082/BN/Mos2 hybrid metal matrix composites synthesized using stir casting process

Abstract

This study examines the wear behaviour of AA6082/x Boron Nitride (BN) (x = 1, 2, 3 wt.%)/1 wt.% of Molybdenum Disulphide (MoS2), a novel hybrid metal matrix composite (MMC), under dry sliding conditions. The composite was fabricated through liquid-state processing, i.e., stir casting. A pin-on-disk tribometer was used to estimate the coefficient of friction (COF) and wear rate by varying tribological process parameters under dry sliding conditions. The results show that at the maximum load of 40 N, the wear rate of the unreinforced alloy is observed 4.077 × 10−2 mm3/m, while at the AA6082/3 wt. of %, BN/1 wt. % of the MoS2 composite's wear rate is reduced to 2.162 × 10−2 mm3/m. Further, the wear rate increases as the sliding distance increases from 500 m to 2000 m. Moreover, the friction coefficient of the unreinforced alloy is observed 0.37, whereas the AA6082/3 wt.% of BN/1 wt.% of MoS2 composites is observed 0.31 under reduced loads. It might be due to the presence of hard ceramic BN and MoS2 reinforcements enhancing the developed composite's resistance to wear by forming a mechanically mixed layer (Fe2O3) on the sliding contact surface. Moreover, the novel hybrid composite materials exhibit a lower coefficient of friction at higher sliding velocities, sliding distances, and applied loads. However, minimal fine grooves with limited abrasion are observed on the worn surface, which was examined through a scanning electron microscope.