Abstract: Using a technique of relative optical interference intensity (ROⅡ) , the nanotribological properties of ultrafine diamond powder as additive is investigated. Results have shown that the effect of viscosity of global diamond nanoparticles gives rise to thicker film in thin film lubrication regime. Its effect of tiny ball bearing leads to a lower friction coefficient . The tribological process is one that the ultrafine diamond powder is dispersed and reunited continuously and exhibits time effect.

Key words: Effect of tiny ball bearing, Thin film lubrication, Ultrafine diamond powder