Tribological properties of a CrN coating containing carbon nanoparticles

CrN is well known to be one of the most performing tribological coatings, with excellent wear and corrosion resistance and good toughness. These last two properties could make CrN a promising base for the development of coatings for high pressure contacts in lubricated conditions. Unfortunately, like most other nitrides, its dry friction coefficient is not very low. In this work we present the results of a series of experiments aimed at investigating the effect of the incorporation of carbon nanoparticles (nC) on the tribological properties of CrN, in order in particular to check the possibility of achieving a lower dry friction coefficient. Taguchi DoE technique was used to define the set of experiments to be performed; the analysis shows that only minor changes in both dry and lubricated friction coefficient can be obtained within the range of deposition parameters investigated while microhardness is sensitive to variations of the deposition pressure.