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Документ Structural engineering and functional properties of vacuum-arc coatings of high-entropy (TiZrNbVHf)N and (TiZrNbVHfTa)N alloys nitrides(Institute for Single Crystals, 2019) Sobol, O. V.; Dur, Osman; Postelnyk, A. A.The effect of nitrogen pressure during the deposition of vacuum-arc (TiZrNbVHf)N and (TiZrNbVHfTa)N coatings on their phase-structural state, substructure and resistance to abrasive wear was investigated. It was established that in multi-element (based on high-entropy alloys) (TiZrNbVHf)N and (TiZrNbVHfTa)N coatings obtained in a nitrogen atmosphere in the range of nitrogen pressures PN = 2.5 ·10-4-4.5 ·10-3 Torr, a single-phase state is formed (based on cubic crystal lattice of structural type NaCl). The use of a multi-element composition with a single-phase state with a cubic lattice allows for (Ti-V-Zr-Nb-Hf-Ta)N coatings to achieve high microstrain values (up to 1.2 %) at low deposition pressure. It was found that high-entropy nitride coatings with low abrasive wear are characterized by a crystallite grain size of less than 50 nm, the absence or low level of texture perfection [111], and the presence of a rather high microstrain in crystallites (reaching 1.2 %). The reasons for the observed changes in the structural state and substructure of multi-element nitride coatings and their effect on abrasive resistance are discussed.Документ А Computer Simulation of Radiation-Induced Structural Changes and Properties of Multiperiod ZrNₓ/MoNₓ System(Sumy State University, 2017) Sobol, O. V.; Meylekhov, A. A.; Bochulia, T. V.; Stolbovoy, V. A.; Gorban, V. F.; Postelnyk, A. A.; Shevchenko, S. M.; Yanchev, A. V.Influence of the period value Λ (at different negative potential Ub that supplied during deposition) on phase composition, structure, stress-strain state and hardness of multiperiod coatings ZrNₓ/MoNₓ is investigated by using complex methods of validation structural state at combined with microindentation. Formation in layers ZrNx and MoNx the phases with cubic lattice and preferred orientation of crystallites with axis [100] is established. Stress-strain state of compression with increasing Ub is amplified and reaches maximum value (– 6.7 GPa) at Λ = 20 nm and Ub – 110 V. Hardness of coating increases with decreasing Λ from 300 to 20 nm. Coatings that obtained with Λ = 20 nm and Ub – 110 V have the highest hardness 44 GPa. Relaxation of structural compressive stresses and decreasing hardness is happening at smaller Λ and larger Ub – 110 V (as a result of radiation-stimulated forming defect and mixing). Data of computer modeling of defectiveness at atomic level at bombardment of ions that accelerated in field Ub are used to explain the results.Документ Structural Engineering and Mechanical Properties of (Ti-V-Zr-Nb-Hf-Ta)N Coatings Obtained at Different Pressures(Сумський державний університет, 2019) Sobol, O. V.; Andreev, A. A.; Postelnyk, H. O.; Meylekhov, A. A.; Sagaidashnikov, Yu. Ye.; Stolbovoy, V. A.; Yevtushenko, N. S.; Syrenko, T. O.; Kraievska, Zh. V.; Zvyagolskiy, A. V.Effect of pressure of the reaction gas on the texture, structural stress state and mechanical properties (hardness and resistance to abrasive wear) in vacuum-arc coatings based on Ti-V-Zr-Nb-Hf-Ta nitrides of high entropy alloys were investigated in this work. At a bias potential of – 200V, an increase in nitrogen pressure during deposition from 2.5·10⁻⁴ to 4.5·10⁻³ Torr leads to an increase in the content of nitrogen atoms in the coating, and the formation of a bittexture state [111] + [311] is established. The formation of a biaxial texture occurs due to the presence in alloys of atoms with very different masses (Ti, V and Hf, Ta). The use of a multi-element composition in a single-phase state with a simple cubic lattice allows to achieve high values of microstrain (up to 1.4 %) with a low deposition pressure. It is determined that the increase of nitrogen pressure during deposition leads to an increase in macrostresses. The highest hardness of 53 GPa is achieved in coatings obtained at a pressure of 2·10⁻³ Torr. It has been established that coatings with high resistance to abrasive wear are found to be: crystallite grain size 12-25 nm, absent of texture (or a low level of texture perfection), and also rather high microstrain in crystallites.