Numerical simulation of mixed lubrication considering surface forces

Publication date: Available online 18 July 2019Source: Tribology InternationalAuthor(s): Shuowen Zhang, Chenhui Zhang, Yuanzhong Hu, Liran MaAbstractMixed lubrication describes a lubrication regime where elastohydrodynamic lubrication and asperity contact coexist. Surface spacing is expected to be small during the interaction between nano-scale smooth surfaces. When alkali metal salt solution is applied as lubricant, short-range surface forces are incorporated into an existing model to simulate mixed lubricated non-conformal sliding contact. The new model is examined in a wide range of sliding velocities to demonstrate the effect of surface forces at different lubrication regime, from boundary lubrication to full film hydrodynamic lubrication. It is revealed that surface forces reduce friction coefficient particularly at mixed lubrication regime. Reduction of surface roughness improves contribution of surface forces and makes it easier to achieve superlubricity at low speed.
Source: Tribology International - Category: Materials Science Source Type: research