Influence of Nb addition on the structure, composition and properties of single-layered ZrN-based coatings obtained by vacuum-arc deposition method

The paper deals with the vacuum-arc deposition of single-layered ZrN-based coatings with and without the addition of niobium in their composition. We generate metal plasma to synthesize (Zr,Nb)N coatings by evaporation of two cathodes (Zr and Nb) by vacuum arc. The niobium concentration in the coating was varied by changing the evaporator arc current with the Nb cathode. The article covers study results of the mechanical and tribological properties of the obtained coatings, their elemental and phase composition, and structural state. The present research illustrates the effect of the niobium concentration on characteristics of the ion-plasma (Zr,Nb)N coatings. It demonstrates that the ZrN-based coatings consist of columns that are divided into the ZrN crystallites with a cubic crystal lattice. Furthermore, it shows that addition of niobium to the composition of ZrN-based coatings results in a significant change in their properties such as refinement of their structural components: the lateral size of the columns ≈ 2 times, the average diameter of crystallites ≈ 1.4 times. The single-layered nanocrystalline (Zr,Nb)N coatings, obtained in optimal conditions, have niobium concentration of 9.8 at.%, high hardness (up to 39.4 GPa), low wear rate (9 · 10−6 mm3 N−1 m−1), relatively low roughness (0.03 μm), and a high degree of elastic recovery (up to 60%). •ZrN-based coatings with different niobium concentration were deposited by vacuum-arc deposition method.•Its mechanical and tribological properties, structure, elemental and phase composition are presented.•(Zr,Nb)N coatings with additional niobium doping were nanocrystalline and multiphase and have improved properties.•(Zr,Nb)N coating with niobium concentration of 9.8 at.% showed the best results of hardness and wear resistance.