Micromechanical and Tribological Properties of Nanostructured Carbonitride Coatings Deposited by PVD Technique

Abstract

Nanostructured smart coatings (NSC) based on the TiAlSi-CN composite structure elements were deposited using reactive high-power physical vapor deposition (PVD) technique. The advanced modular deposition system included up to 8 high-power magnetron sputtering devices (MSD) allowing operate them simultaneously and exceed power density of 120 W/cm2 within each device erosion zone. The novel designed NSC on bearing steel 100Cr6 substrates demonstrated enhanced mechanical and tribological properties comparably with bearing steel ones required for multifunctional high-tech applications. The deposited NSC containing TiAlSi-CN nanoparticles strengthened by elemental additives Cr and Nb exhibited microhardness as high as 2500 HV values in comparison with 750 HV of 100Cr6 steel substrates. Load-displacement curves obey Meyer’s power-law surprisingly well because power-trendline fitted ones by R-squared value of 0.9999 for all the film-samples. Tribological properties were measured under dry friction conditions between the bearing steel ball of Ø 6 mm and the film-samples’ flat surface. Coefficient of friction (CoF) ranges between 0.22-0.56 depending on a sample and load. Tribotracks worn under the friction indenter were too shallow to evaluate them by Mitutoyo profilometer SJ-500. Therefore, the wear rate was estimated as ball wear of the friction indenter.