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Документ Formation of Superhard State of the TiZrHfNbTaYN Vacuum–Arc High-Entropy Coating(Allerton Press, Inc., 2018) Beresnev, V. M.; Sobol, O. V.; Andreev, A. A.; Gorban, V. F.; Klimenko, S. A.; Litovchenko, S. V.; Kovteba, D. V.; Meilekhov, A. A.; Postelnyk, A. A.; Nemchenko, U. S.; Novikov, V. Yu.; Maziilin, B. A.Complex studies of the formation of the superhard state in the TiZrHfNbTaYN vacuum-arc high-entropy coating were carried out. Based on the approach of the structural surface engineering, the regularities of the formation of the triads composition–structure–physico-mechanical properties depending on the supplied potential displacement are established. It is shown that the increase of Ub at the formation of a coating leads to a decrease of the relative content of a light (Ti) and increase of a heavy (Ta, Hf) metal components, which is determined by radiationally stimulated processes in a near surface region at the deposition. The formation of the single-phase state (based on the fcc of metal lattice) in the range Ubfrom –50 to –250 V and revealed the formation of the preferred orientation of the crystallites with the axis [111], which is perpendicular to the growth plane. The increase of the perfection of the texture with the [111] axis with increasing Ub is accompanied with an increase of the coatings hardness, which makes it possible to achieve the superhard state (H = 40.2 GPa) at Ub = –250 V.Документ The Use of Negative Bias Potential for Structural Engineering of Vacuum-Arc Nitride Coatings Based on FeCoNiCuAlCrV High-Entropy Alloy(Sumy State University, 2018) Sobol, O. V.; Andreev, A. A.; Gorban, V. F.; Meylekhov, A. A.; Postelnуk, A. A.; Stolbovoy, V. A.; Zvyagolskiy, A. V.The effect of negative bias potential (Ub = – 40, – 110, and – 200 V) upon the deposition of multielement coatings on their composition, structure, and mechanical properties was studied. It is shown that when using a high-entropy multielement (of 7 elements) FeCoNiCuAlCrV alloy, it is possible to obtain a single-phase nitride (FeCoNiCuAlCrV)N. Nitride has an fcc crystal lattice (structural type NaCl). It has been established that with an increase in Ub in the structural state occurs transition from practically nontextured (polycrystalline) to the preferential orientation of the growth of crystallites with the [111] texture axis (at Ub = – 110 V) and [110] (at Ub = – 200 V). This is accompanied by a decrease in the lattice period, as well as a decrease in hardness and modulus of elasticity. For coatings (FeCoNiCuAlCrV) N, the highest hardness of 38 GPa is achieved by using the smallest (– 40 V) bias potential during the deposition process. It is shown that to achieve high hardness at high Ub it is necessary to increase the content in the highentropy alloy of elements with high nitride-forming ability.Документ Influence of the Bias Potential and the Pressure of the Nitrogen Atmosphere on the Structure and Properties of Vacuum-arc Coatings Based on the AlCrTiZrNbV High-entropy Alloy(Sumy State University, 2018) Sobol, O. V.; Andreev, A. A.; Gorban, V. F.; Postelnyk, A. A.; Stolbovoy, V. A.; Zvyagolskiy, A. V.The effect of the constant bias potential (Ub) supplied to the substrate upon condensation and pressure of the nitrogen atmosphere (PN) on the elemental composition, growth morphology, texture, and physical-mechanical characteristics of vacuum-arc (AlCrTiVZrNb)Nx coatings is studied. It is established that with increasing Ub from – 110V to – 200V, the axis of preferential growth of crystallites of the fcc phase from [100] to [110] changes. Such a change is accompanied by a decrease in the hardness (H) and the ratio H/E (where E is the modulus of elasticity). The conditions for the formation of the preferential orientation of the crystallites (axial texture) of vacuum-arc (AlCrTiVZrNb)Nx coatings and the influence of texture on mechanical properties are discussed. It was established that the change in PN in the range Torr basically allows to vary the degree of filling of the coating with nitrogen atoms. Based on the revealed regularities, the conditions for achieving high hardness for vacuum-arc coatings of nitrides AlCrTiVZrNb high-entropy alloy are substantiated. Because of the presence in the alloy of elements with a relatively low heat of nitride formation, in order to achieve high hardness, it is necessary to use deposition conditions with relatively low energy of bombarding atoms. The use of a low Ub = –110 V at the highest pressure Torr allows achieving an superhard state with a hardness of 44 GPa.