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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 Structure and Properties of Vacuum-arc Coatings of Chromium and Its Nitrides Obtained under the Action of Constant and Pulse High-voltage Bias Potential(Sumy State University, 2017) Sobol, O. V.; Postelnyk, A. A.; Mygushchenko, R. P.; Al-Qawabeha, Ubeidulla F.; Tabaza, Taha A.; Al-Qawabah, Safwan M.; Gorban, V. F.; Stolbovoy, V. A.To reveal the regularities of structural engineering of vacuum-arc coatings based on chromium and its nitrides, the influence of the main physicotechnological factors (the pressure of the nitrogen atmosphere and the bias potential) in the formation of coatings was studied. It was discovered that during the deposition of chromium coatings the formation of the texture axis [100], as well as the macrodeformation of compression is happening. The supply of a high-voltage negative pulse potential to the substrate increases the mobility of the deposited atoms and leads to relaxation of the compression deformation. As the pressure increases from Torr, the phase composition of the coatings changes: Cr (JCPDS 06-0694) → Cr2N(JCPDS 35-0803) → CrN(JCPDS 11-0065). The supply of high-voltage pulses leads to the formation of a texture of crystallites with parallel growth surfaces planes having d ≈ 0.14 nm. The structure obtained by pulsed high-voltage action makes it possible to increase the hardness of the coating to 32 GPa and reduce the friction coefficient to 0.32 in the "chromium nitride-steel" system and to 0.11 in the "chromium nitride-diamond" system. The results obtained are explained from the viewpoint of increasing the mobility of atoms and the formation of cascades of displacements when using an additional high-voltage potential in the pulse form during the deposition of chromium-based coatings.Документ Mixing on the Boundaries of Layers of Multilayer Nanoperiod Coatings of the TiNх/ZrNх System: Simulation and Experiment(Sumy State University, 2017) Sobol, O. V.; Meylekhov, A. A.; Mygushchenko, R. P.; Postelnyk, A. A.; Sagaidashnikov, Yu. Ye.; Stolbovoy, V. A.Using the complex of methods for attestation of the structural state in combination with computer simulation and measurement of mechanical properties (hardness), the influence of the period Λ on the mixing process on the interlayer boundaries of multilayer coatings TiNх/ZrNх is studied. The formation of two phases (TiN and ZrN) with one type of crystal lattice (structural type NaCl) is identified in the layers of multiperiodic compositions TiNx/ZrNx with a period of Λ = 20 ... 300 nm. At Λ = 10 nm, the formation of a solid solution (Zr, Ti)N, as well as a small volume of the TiN phase is revealed on XRD spectras. The presence of TiN component is due to the larger initial value of the layer based on titanium nitride. To explain the results obtained, the results of computer simulation of damage at the atomic level during bombardment by ions accelerated in the Ub field are used. The critical thickness of mixing (about 7 nm) in the TiNx/ZrNx system is determined upon condition that Ub = – 110 V. It is established that a decrease in the period from 300 to 20 nm leads to increase in hardness. The highest hardness of 44.8 GPa corresponds to the superhard state. It is established that the critical thickness of radiation-stimulated defect formation has a significant effect on the stress-strain state and hardness of coatings with a small Λ ≈ 10 nm. In this case, relaxation of the stress-strain compression state occurs and the hardness decreases. However, the formation of a solid solution, while retaining part of the unreacted layer of titanium nitride at Λ = 10 nm, makes it possible to obtain an ultrahigh (44.8 GPa) hardness of the coating.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.Документ Влияние высокоэнтропийных составляющих нитридных слоев на содержание азота и твердость вакуумно-дуговых многослойных покрытий (TiN-Cu)/(AlNbTiMoVCr)N(Сумський державний університет, 2016) Береснев, В. М.; Соболь, Олег Валентинович; Литовченко, С. В.; Немченко, У. С.; Столбовой, Вячеслав Александрович; Колесников, Д. А.; Мейлехов, Андрей Александрович; Постельник, Анна Александровна; Турбин, П. В.; Маликов, Л. В.Используя методы элементного анализа, рентгеноструктурных исследований и измерения микротвердости, необходимые для проведения комплексных исследований по схеме: состав – структура – свойства, исследованы возможности структурной инженерии многослойных (TiN-Cu)/(AlNbTiMoVCr)N покрытий. Установлено, что введение второго слоя из высокоэнтропийного сплава даже при относительно малом содержании составляющих элементов (до 1 мас. %) сопровождается формированием фазы на основе ГЦК решетки твердого раствора. Переход от однослойных TiN-Cu покрытий к многослойной системе (TiN-Cu)/(AlNbTiMoVCr)N сопровождается повышением относительного содержания азота в покрытии и ростом твердости, достигающей 24,5 ГПа.Документ Влияние на механические характеристики толщины слоев в многослойных покрытиях MoN/CrN, осаждаемых под действием отрицательного потенциала смещения(Сумський державний університет, 2016) Береснев, В. М.; Соболь, Олег Валентинович; Столбовой, А. В.; Литовченко, С. В.; Колесников, Д. А.; Немченко, У. С.; Мейлехов, Андрей Александрович; Постельник, Анна АлександровнаС использованием метода структурной инженерии в работе проведено комплексное исследование влияния толщины слоев многослойной композиции MoN/CrN при действии постоянного отрицательного Ub на фазово-структурное состояние и механические характеристик покрытий. Выявлено, что в составляющих (Cr-N и Mo-N) слоях формируются фазы с изоструктурной кубической (типа NaCl) кристаллической решеткой с осью текстуры [311] при малом Ub = – 20 В и [111] при большом Ub = – 150 В. Установлено, что перемешивание в межграничной области слоев при больших Ub = – 150 В приводит к резкому снижению механических свойств при толщине слоев h ≤ 40 нм. Наивысшая твердость 39,8 ГПа и абразивная прочность для LC5 = 145 Н, была достигнута для h ≈ 12 нм при подаче малого Ub = – 20 В.Документ Структурная инженерия вакуумно-дуговых многослойных покрытий ZrN/CrN(Сумський державний університет, 2016) Соболь, Олег Валентинович; Андреев, Анатолий Афанасьевич; Горбань, Виктор Федорович; Мейлехов, Андрей Александрович; Постельник, Анна Александровна; Столбовой, Вячеслав АлександровичДля многослойной системы ZrN/CrN с большим различием по атомным массам и радиационно-стимулированному дефектообразованию металлических составляющих, проанализировано влияние толщины слоев (в нанометровом диапазоне) и подаваемого при осаждении отрицательного потенциала смещения (– Us) на структуру и твердость композиционных вакуумно-дуговых покрытий. Установлено, что при толщине слоев менее 50 нм подача – Us приводит к росту микродеформации в слоях CrN при бомбардировке их ионами Zr с большим атомным радиусом и массой, а в слоях ZrN наблюдается релаксация деформации. Наблюдаемые эффекты объяснены повышением энергии осаждаемых ионизированных частиц при подаче – Us, что определяет радиационно-стимулированное перемешивание на межфазных границах слоев и приводит к падению твердости. Наибольшая твердость 42 ГПа в системе ZrN/CrN достигается при осаждении тонких (20 нм) слоев в отсутствии – Us.Документ Structural Engineering Multiperiod Coating ZrN/MoN(Sumy State University, 2016) Sobol, O. V.; Meylekhov, A. A.; Stolbovoy, V. A.; Postelnyk, A. A.Using the method of structural engineering by changing the thickness of the layers in a multiperiod ZrN/MoN system investigated the effect of the phase-texture state of the crystallites and their size on the hardness of the vacuum-arc coating. Is revealed a determining influence on the formation of ZrN layers preferential orientation growth [100] axis with a small layer thickness 7-20 nm (the deposition of 3 to 10 seconds). At high layer thickness determines the texture [311] crystallites are - Mo2N phase formed in the Mo-N layers. Pulsed high-voltage stimulation without changing the type of structural states for different layer thicknesses, leads to partial disorientation texture in thick layers. Hardness of coating with thick (80 nm) layers is 35-37 GPa. In small thickness layers pulse stimulation of atoms motility causes the formation of a planar structure with an average crystallite size of 4-9 nm in the layers, which is accompanied by increased hardness of up to 44 GPa.Документ The Effect of Constant and High Voltage Pulse Bias Potentials on the Structure and Properties of Vacuum-Arc (TiVZrNbHf)Nₓ Coatings(Sumy State University, 2018) Sobol, O. V.; Postelnyk, A. A.; Mygushchenko, R. P.; Gorban, V. F.; Stolbovoy, V. A.; Zvyagolskiy, A. V.The effect of constant (Ub) and high voltage pulse (Uip) bias potentials supplied to the substrate during condensation, on the structure and properties of vacuum-arc (TiVZrN-Hf)Nх coatings has been studied. It has been determined that the number and size of the drop phase decreases with increasing Ub. The use of Uip promotes a more uniform growth in the coating volume. It is shown that due to the increase of Ub from 0 to 200 V in nitride coatings of high entropy alloys, it is possible to change the growth texture [100] to [111]. This results in increased hardness from 32 GPa to 49 GPa. The supply of high voltage potential in a pulse form leads to a relative decrease in the average size of crystallites and the formation of a bi-texture state. Conditions and mechanisms of the preferential crystallites orientation (axial texture) of vacuum arc (TiVZrNbHf)Nх coatings and texture influence on mechanical properties have been discussed.Документ The Influence of Layers Thickness on the Structure and Properties of Bilayer Multiperiod Coatings Based on Chromium Nitride and Nitrides of Transition Metals Ti and Mo(Sumy State University, 2018) Sobol, O. V.; Meylekhov, A. A.; Mygushchenko, R. P.; Postelnyk, A. A.; Tabaza, Taha A.; Al- Qawabah, Safwan M.; Gorban, V. F.; Stolbovoy, V. A.The influence of the layers thickness of bilayer multi-period coatings of the CrNx/MoNx and CrNx/TiNx systems on their phase-structural state, substructure, stress-strain state and mechanical properties was studied using methods of precision structural analysis in combination with computer simulation of implantation processes during particle deposition. It is established that a two-phase structure of CrN and-Mo2N phases of the structural type NaCl is formed in the multi-period coatings of the CrNx/MoNx system with a nanometer thickness of the layers. Because of the small difference in periods (less than 0.5 %) for Λ = 20 nm, the layers form a coherent interlayer interface. The use of small Ub – 20 V during deposition makes it possible to avoid significant mixing at interlayer (interphase) boundaries even at the smallest Λ = 10 nm. Nitride layers formed under conditions of vacuum arc deposition are under the action of compressive stresses. In the СrNх/TiNх system, because of the relatively large discrepancy between periods (more than 2.5 %), during the formation of the same structural components in the layers (CrN and TiN phases of the structural type NaCl), the epitaxial growth with period adjusting does not occur, even for the smallest Λ = 10 nm. The action of the deformation factor at the interphase boundary allows achieving an ultrahard state (with a hardness of about 50 GPa), which causes a relatively low friction coefficient. The obtained results on the formation of phase-structural states with the nanoscale thickness of layers of multi-period nitride coatings are explained from the position of minimization of surface energy and deformation energy.