MECHANISM AND CHARACTERS OF THIN-FILM LUBRICATION AT NANOMETER-SCALE

Thin film lubrication is a transition region between elastohydrodynami c lubrication and boundary technique of relative optical interference intensity with the resolution of 0.5 nm in the vertical direction and 1.5 mu m in the horizontal direction is used in a pure rolling process to measure the film thickness with different lubricants, speeds, load s and substrate surface energy. Experimental data show that the charac teristics of thin film lubrication are different from those of elastoh ydrodynamic lubrication and boundary lubrication. As the rolling speed decreases, a critical film thickness on be found to distinguish thin film lubrication from elastohydrodynamic lubrication. Such thickness i s related to the substrate surface energy, atmospheric viscosity of lu bricant, etc. A physical model of thin film lubrication with the fluid layer, the ordered liquid layer and the adsorbed layer is proposed an d the functions of these different layers are discussed.