Synergistic Lubrication of Diamond-Like Carbon and Poly-Α-Olefin Oil: Coupled Dependence on Oil Viscosity and Applied Load

Abstract

Diamond-like carbon (DLC)/poly-α-olefin (PAO) composite system attracts attention in reducing the tribo-induced risks for mechanical mobility systems. However, the coupled effect of applied load and PAO viscosity on tribological behavior of DLC/PAO system, which causes the transition between different lubrication states of mated surfaces, and the synergistic mechanism remain unclear. We fabricated the DLC/PAO system, and the tribological properties induced by both PAO viscosity and applied load were investigated. Results indicated that under low applied load, the system with moderate PAO viscosity exhibited the best tribological performance. Moreover, the variations of them affected the distribution and load-bearing capacity of oil, interfacial graphitization degree, formation of lubricating oil film, which brought complicated effect on tribological properties of composite system.

Keywords: diamond-like carbon, poly-α-olefin, viscosity, load