Comparison of tribological characteristics of nanostructured TiN, MoN, and TiN/MoN Arc-PVD coatings

Abstract

The tribological properties of TiN, MoN, and TiN/MoN coatings have been investigated. It has been shown that, for multilayer (alternate) TiN/MoN coatings, a maximum hardness reaches 29–31 GPa that is significantly less than the hardness of MoN coatings (36.0–40.2 GPa) when changing the deposition conditions. MoN coatings possess lower coefficients of friction compared to TiN coatings, in particular at the initial stages of a scratch test. Two mechanisms of destruction are revealed by the adhesion tests, i.e., a cohesive failure with a minimum critical loading L C1 and an adhesive test (plastic abrasion) with the appearance of a first crack L C2. The resistance of multilayer (nanoscale) nanostructured TiN/MoN coatings with a total thickness of up to 8 μm is greater than that of TiN coatings.