Individual and combined effects of introducing DLC coating and textured surfaces in lubricated contacts

This article analyses two types of surface modifications: DLC coating and texturing, together with their combined effect in lubricated contacts. Surfaces were textured using photolithography and chemical etching, whereas DLC coatings were deposited using the magnetron sputtering technique. The effect of these modifications on the friction coefficient and the failure mechanism of the surfaces are studied by means of ball-on-disc tests in a tribometer. A wide range of experimental conditions are covered, which includes from full film conditions to boundary lubrication. The results show a significant reduction in the friction coefficient mainly under severe working conditions. The analysis of the thermal effects and the wear track adds information that contributes to explain the friction reduction.