Tribological properties of Al2O3 nanoparticles as lubricating oil additives

Nano-scale Al2O3 spherical particles, prepared via a hydrothermal method and modified by silane coupling agent, can be well-dispersed in lubricating oil. The tribology properties of Al2O3 nanoparticles as lubricating oil additives have been studied by four-ball and thrust-ring friction test, which illustrate that the modified Al2O3 nanoparticles can effectively improve the lubricating behaviors compared to the base oil. When the added concentration is 0.1 wt%, the friction coefficient and the wear scar diameter are both smallest. The lubrication mechanism is that a self-laminating protective film is formed on the friction surface and the wear behavior changes from sliding friction to rolling friction. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.