Vol.26, No.1, 2026, pp. 125–130
https://doi.org/10.69644/ivk-2026-01-0125

Tribological behaviour of Al-based automotive alloy is studied using pin-on-disc wear testing apparatus under different levels of used motor oil. Throughout the investigation, different pressures are applied but the sliding speed is constant. Experimental results prove that higher levels of used motor oil have a large negative influence on the tribological behaviour of the alloy. The oil acts as a lubricant by creating a thin film between the contacting surfaces which controls the wear characteristics. Application of long-used oils exhibits high wear rates with high friction coefficients due to quality loss in oil purity, viscosity, density, etc. Microscopical examination of the worn surfaces in a sliding environment of fresh oil reveals plastic deformation and micro-scuffing caused by oil film's resistance. In contrast, narrow grooves, random crevices and deep marks are formed under used oil for its harmful and corrosive nature along with increased surface contact.

Keywords: • automotive Al-alloy • wear • friction • used motor oil • microstructure