Friction-Reduction and Wear-Resistance of Single-Crystal Diamond Enhanced Via Metal Oxide Abrasive

Abstract

The purpose of this work is to enhance the friction-reduction and wear-resistance and systematically explain regulation mechanism of single-crystal diamond (SCD) via the addition metal oxide abrasive acted as a solid lubrication. Ultra-low friction and wear-resistance mechanism is revealed via the observations of worn surface morphology and wear debris microstructure. Experimental results show that metal oxide abrasive can enhance the friction-reduction of SCD, owing to the co-action of the tribo-chemical reaction (graphitization efficiency) and Molecular Bearing (Wear Debris Rolling Friction) Effect. The metal oxide abrasives hinder the direct contact of SCD, release the interface contact stress, and effectively improve the resistance to adhesive wear and fatigue wear. Al2O3 and Coup nano-particles abrasive resulted in a lower friction coefficient and compared with Al2O3 and ZrO2, which is attributed to graphitization, Abrasive shape, size and structure. The excellent anti-wear performances of Fe2O3, Al2O3 and CuO benefit from the continuous coverage and hardness of the abrasive.

Keywords: Single-crystal diamond, Metal oxide, Wear and Tribology, interfaces, Phase transformation, Adhesion