Enhancement in tribological performance of plastic oil by solid lubricant additives

Abstract

In this study, plastic oil (PO) as a potential lubricant was investigated. The base PO was incorporated with graphene nanoplatelets (GNP) and hexagonal boron nitride (hBN) nano additives in varying concentrations to form nano lubricants. Their viscosity, tribological, acidic/basic nature, thermal degradation and dispersion stability properties were investigated. It was observed that 1.5 wt% GNP and 1.0 wt% hBN added separately to the base PO, provided the lowest coefficient of friction (COF) and wear volume. Based on these lowest COF and wear volume insights, three nano lubricant mixtures were formulated by incorporating both GNP and hBN at different combinations using base PO. Positive synergistic behaviour was observed for COF (49%–60% reduced) and wear volume (90%–97% reduced) for two combination mixtures compared to the base PO. These improvements in the mixture were due to the polishing, mending mechanisms and tribofilm that protected the interacting surfaces.

Tribological Performance of a Plasma Electrolytic Oxidation-Coated Mg Alloy in Graphene-Incorporated Ethanol

“…In some other tribological systems, friction reduction mechanisms in oil-based lubricants that incorporate graphene have been investigated. These mechanisms include the formation of protective boundary films [16][17][18][19][20][21][22][23][24][25][26][27], the reduction of surface roughness and asperity contact [28][29][30][31], the enhancement of load-bearing capacity [32,33], and the improvement of lubricant viscosity and rheological properties [34,35]. A few studies have examined the tribological properties of graphene and its derivatives in water [36,37] and ethanol [38,39], recognizing the benefits of these solvents in preventing the agglomeration of GNPs due to their polar nature, which is imparted by -OH groups.…”