Enhanced extreme pressure and tribological performance of hybrid nano lubricant

ABSTRACT The present study reports the tribological performance of a novel hybrid nano-lubricant for bronze/AISI 4340 alloy-steel tribopair. The hybrid nano-additive used in the present study helps to improve the lubricity and can sustain under extreme conditions. Initially, friction and wear properties are recorded by varying concentrations of Al2O3 (0.5, 0.8, 1.0, and 1.5 wt. %) and GNP (0.05, 0.1, 0.2, and 0.5 wt. %). Based on the results, an optimum hybrid concentration (OHC) is prepared by adding 0.8 wt. % of Al2O3 and 0.2 wt. % of GNP which resulted in 83.84% and 79.75% reductions in coefficient of friction (COF) in comparison to optimum Al2O3-based and GNP-based lubricants, respectively. However, the wear volume (WV) for OHC lubricant indicated 98.28% and 75% reduction in comparison to the above-mentioned lubricants, correspondingly. Extreme pressure (EP) tests were carried out and OHC lubricant reported improved weld point for hybrid nano additive-based lubricant. GRAPHICAL ABSTRACT