Tribological Study of Molybdenum Nitrides Under the Effect of Vanadium

Abstract

Our study of the MoVN ternary thin films has the objective of improving certain tribological and mechanical characteristics and of finding the appropriate stoichiometry to have the microstructure that corresponds to the desired properties using the characterization techniques: SEM -XRD-EDS-XPS- WDS. Nano-indentation and the scrash-test. Note that wear and friction resistance does not depend on the internal characteristics of the materials in contact as is usually the case for mechanical properties, but rather depends mainly on the structure and morphology and experimental conditions. Hypotheses will be presented in order to explain the tribological behavior of deposits and to match them to their physicochemical and mechanical properties. The EDS-XPS microanalyses revealed that the atomic ratio (N/V) ~ 1 for VN, that (N/Mo)  1.22 for MoN and that (N/(Mo + V))  1 for the MoVN ternary films. From this figure we find that the MoN film has an average coefficient of friction of 0.65. This film then has good wear resistance. Comparing this value with that obtained on MoN coatings deposited by the Alcatel PVD sputtering system on AISI substrate, (which is of the order of 0.45) therefore better than that deposited on XC100 and Si . This variation can be explained by the nature that differs between the coating/substrate interface and the other links that are generated. By comparing the Mo-V-N and MoN films, we can then say: increasing the V content in the Mo-V-N film is more favorable for the production of films with a low average value of the coefficient of friction. Which remains lower than that of MoN film (0.65)? So this is regular with the mechanical properties.