Lubrication performance of 5CB liquid crystal combined with different wear-resistant coatings on friction surface

Abstract

The tribological behaviors of chromium-based ceramic composite coating (CCC) and diamond-like carbon coating (DLC) are investigated by reciprocating sliding experiments, respectively, under lubrication conditions with and without 5CB liquid crystal additives. The addition of 5CB significantly improves the lubrication performance and protects the coatings, which is attributed to the formation of a thin lubricating film on the friction surface by 5CB molecules. The reduction in friction and wear of the CCC friction pair is more obvious, implying that the formation of the lubricating film is affected by the coating. These findings suggest a great potential for the use of liquid crystal lubricant additive in combination with solid wear-resistant coatings, which is helpful for the development of high-performance lubrication systems.