Coupling effect of boundary tribofilm and hydrodynamic film

Abstract

Summary: Reducing the friction and wear of dynamic interfaces has been a constant endeavor in the field of sustainability. Lubricants with two-dimensional atomic materials are operative frameworks proposed as promising candidates: they can together generate both a boundary tribofilm and a liquid hydrodynamic film in the interfacial domain. However, a quantitative characterization of the film formation and their coupling behaviors in the finite domain is lacking. Here, we report the coupling effect of tribofilms and hydrodynamic films regulated by typical representatives of two-dimensional material family (graphene, hBN, MoS2, and WS2). The anti-wear properties of the interfaces are attributed to the behavior of the tribofilm, whereas the anti-friction properties of the interfaces are attributed to the viscosity behavior of the hydrodynamic film. This study provides an understanding of the intrinsic coupling mechanism of a tribofilm and a hydrodynamic film and a possible strategy for the design of interfacial lubricating systems.

Keywords

• tribofilm
• hydrodynamic film
• 2D materials
• lubrication