Lubrication improvement and friction reduction of DLC-coated sliding surfaces by in-process structuring and post polishing

The paper describes an experimental investigation on the influence of the surface roughness of diamond-like hard carbon (DLC) coatings on the friction and wear in sliding contact against steel under conditions of starving lubrication. Experimental studies employed a reciprocating ball-on-fiat tribometer in two different modes of operation. The study showed a microlubrication effect in terms of lubrication assistance achieved by microscopic cavities in the topography of a DLC coating and good sliding behaviour even in the case of starving oil lubrication. Post-process polishing of the coated surfaces was adopted for eliminating unnecessary friction losses due to asperity interactions and micro-abrasive wear.