Structural, mechanical and tribological properties of Cr-V-N coatings deposited by cathodic arc evaporation

The Cr1−xVxN monolayer coatings were synthesized using vacuum arc plasma flux method. The properties of the coatings were compared with CrN and VN, i.e. for coatings where x = 0 or 1. The surface morphology, microstructure and chemical composition of (Cr,V)N coatings were investigated using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM), X-ray Diffraction (XRD) and Energy Dispersive X-ray Spectroscopy (EDS). The mechanical and tribological properties of coatings were characterized using nano-indentation, scratch test and Daimler-Benz test and ball-on-disk tribometer. It was found that the cubic CrN phase was formed. In coatings with vanadium the solid solution (Cr,V)N phase was observed. The diffraction lines of the coatings were shifted to lower angles which indicated the stress occurring there. The roughness parameter Ra increased linearly with vanadium concentration, from about 0.05 µm (CrN) to about 0.13 µm (VN) which was probably connected with significantly higher number of surface defects. The hardness and elastic modulus of Cr1−xVxN coatings increased from 20 GPa (CrN) to 35 GPa (VN) and 300 GPa (CrN) to about 500 GPa (VN) respectively. Adhesion of the coatings was very high. The critical load of the complete coating detachment exceeds 100 N. The highest wear rate was for CrN coating - (1.7 ± 0.1) × 10−6 mm3/Nm, while the lowest was for VN coating - (1.2 ± 0.6) × 10−7 mm3/Nm. The wear mechanism for all coatings against Al2O3 ball was mainly abrasive. The VN coating showed the lowest friction coefficient in the set of coatings investigated. •Cr-V-N coatings were deposited using cathodic arc evaporation.•Roughness of Cr-V-N coatings increases with vanadium concentration.•Hardness of Cr-V-N coatings increases with vanadium concentration.•Coefficient of friction of Cr-V-N coatings decreases with vanadium concentration.•The wear rate of Cr-V-N coatings decreases with vanadium concentration.