Influence of N concentration on structure and properties of (AlCrMoTiV)Nx films by co-filter cathodic vacuum arc deposition

Abstract

A novel four-arc co-filter cathodic vacuum arc deposition technique which was optimized was introduced to deposit (AlCrMoTiV)Nx high-entropy alloy nitride films that were corrosion-resistant, high hardness and adhesion. The effect of nitrogen on the microstructure, corrosion resistance and mechanical properties of films was systematically investigated. As the N2 gas flow rate continues to increase, the phase structure of the (AlCrMoTiV)Nx films transforms from a body-centred cubic structure to an amorphous structure, and then to a nanocomposite structure with nano- crystallites embedded in the amorphous matrix. The hardness of the films is proportional to the ratio of N2:Ar and reaches maximum (34.08 GPa) at a ratio of 7:4. The adhesion of deposited films was higher than 20 N owing to the bombardment of the substrate by energetic ion beams during the deposition of coatings. The enhanced hardness at higher N contents is mainly gives rise to the combined effect of formation of strong metal‑nitrogen bonding, solid solution strengthening, the formation of the nanocomposite structure and ion beam assisted bombardment strengthening. Furthermore, the excellent corrosion resistance can be obtained by the (AlCrMoTiV)Nx films.