Experimental Study on Lubrication Film Thickness Under Different Interface Wettabilities

Abstract

This paper describes some experimental studies about the effect of interface wettability on hydrodynamic lubrication film thickness by a custom-made slider bearing tester. The lubricated contact pair consists of a fixed-incline slider and a transparent disc, and a thin lubrication film can be generated when the disc rotates. The film thickness was measured by interferometry. The wettability of different slider surfaces was evaluated by the contact angle of the lubricant on them. The relationship of film thickness versus disc speed was measured under different liquid–solid interfaces, and the results showed that slider surfaces with strong wettability to the lubricant could generate higher film thickness. Furthermore, case experiments were carried out to validate the hydrodynamic effect by tailored-slippage. By numerical simulations, the experimental findings were tentatively explained with the phenomenon of wall slippage.