Analysis on mechanism of thin film lubrication

It is an important concern to explore the properties and principles of lubrication at nano or molecularscale. For a long time, measurement apparatus for filmthickness of thin film lubrication (TFL) at nano scale havebeen devised on the basis of superthin interferometry technique. Many experiments were carried out to study the lubrication principles of TFL by taking advantages of aforementioned techniques, in an attempt to unveil the mechanism of TFL. Comprehensive experiments were conducted to explore the distinctive characteristics of TFL. Results show that TFL is a distinctive lubrication state other than any known lubrication ones, and serves as a bridge between elastohydrodynamic lubrication (EHL) and boundary lubrication (BL). Two main influence factors of TFL are the solid surface effects and the molecular properties of the lubricant, whose combination effects result in alignment of liquid molecules near the solid surfaces and subsequently lubrication with ordered film emerged. Results of theoretical analysis considering microstructure are consistent with experimental outcomes, thus validating the proposed mechanism.