Synergistic effects of graphene additives and piston ring surface treatment on friction properties of engine oil

Abstract

The use of nano-additives improves the performance of lubricants by minimizing energy loss due to friction and wear. In this study, the tribological properties of cylinder liner-piston ring were improved by modifying monolayer graphene with surfactants. Additionally, surface chemical chromium plating and chemical heat treatment were conducted on the friction surfaces of specially made piston ring samples to further enhance the piston ring friction. The use of nano-additives, specifically 0.05 wt% modified graphene nano-lubricant, exhibited the best lubrication performance. Compared to the base oil, it reduced the friction coefficient by approximately 31.1% and improved the anti-wear performance by approximately 59.6%. In addition, the effect of the graphene nano-lubricant on the friction performance of chromium- plated samples was more substantial than that of the chemically heat-treated samples. Under high-temperature and heavy-load conditions, the friction coefficient was reduced by 15.5% and 34%, respectively, when compared to the base oils. This can be attributed to the porous surface of the chromium-plated sample, which promotes the storage of the graphene nano-lubricant. The findings of this study highlight the synergistic effect of graphene additives and piston ring surface treatment on the tribological performance.

Impact of tribofilm on the anti-wear and friction-reduction properties of interfaces

“…Numerous friction pairs within the internal combustion machine are important for proper operation. However, these friction pairs contribute to an energy loss of 17%-19% of the engine's energy total energy output and cause a significant impact on wear [1,2]. Engine lubricants play a crucial role in ensuring the performance of combustion engines by reducing friction loss and wear.…”