Nyemchenko U. Peculiarities of formation of vacuum-arc nitride coatings based on high-entropy alloys

The patterns of phase composition, structural state, mechanical and tribotechnical properties of nitride multicomponent coatings based on (TiZrNbMe)N, where Me: Cr, Si, Hf, V, Ta, obtained by means of vacuum-arc spraying of unit cast multielement high-entropy targets have been studied. The presence of strong nitride forming elements in a high-entropy alloy causes formation of coatings, the structural state of which is formed of both fcc and bcc phases, depending on physical and technological deposition parameters. It is found that the diffraction spectra of the coatings that are obtained at the highest pressure of nitrogen of 0.665Pa (TiZrNbAlCrY)N, where Cr was added as the alloying element (atomic radius is 0.125nm) contain diffraction peaks of both bcc and fcc phase, compared to the coatings (TiZrNbAlY)N, with a period of 0.437nm and 0.453nm and the average size of crystallites of 7nm. As for the coating (TiZrNbCr)N and (TiZrNbCrSi)N, despite the large number of constituent metallic components and different tendency of its elements to formation of nitrides, a single phase state based on fcc lattice is formed in the coatings, which in the case of nitrides has NaCl structural type. The value of lattice period in a direction of crystal growth is 0.433nm for the coatings (TiZrNbCrSi)N, and 0.441nm for the coatings (TiZrNbCr)N.