Thermal Stability of Superhard Nitride Coatings Based on Multicomponent high-entropy Ti-V-Zr-Nb-Hf Alloy

Abstract

Nitride coatings with high hardness (60.0-65.0 GPa) are produced from a high-entropy multicomponent single-phase alloy containing five nitride-forming elements by vacuum-arc deposition with application of impulse implantation. These high values of hardness are characteristic of metals that make up the equiatomic alloy only in nanostructured state. The mechanical properties of the coatings annealed in the temperature range up to 1200 °С are studied. Is established that the coatings are solid solutions of high-entropy nitride based on cubic fee lattice. The vacuum coating inherits the same tape of crystal lattice, which is fixed in the target (bcc). The crystal lattice of high-entropy vacuum coatings is formed through the mechanism revealed in the cast alloys. The parameter of this lattice is close to the lattice parameter calculated by Vegard‘s rule.