Кафедри
Постійне посилання на розділhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/35393
Переглянути
50 результатів
Результати пошуку
Документ Structure and properties of multi-period vacuum-arc coatings based on chromium nitride(Institute for Single Crystals, 2020) Postelnyk, H. O.; Sobol, O. V.; Kucerova, L.; Dur, OsmanThe properties of multi-period nanocomposite coatings based on chromium nitride are considered. The effect of the negative bias potential on the phase-structural state and mechanical characteristics of the coatings was investigated by X-ray diffractometry combined with the study of hardness by nanoindentation, surface roughness and coefficient of friction during scratch testing. It has been established that all the systems are characterized by the formation of a cubic crystal lattice of the structural type NaCl, as well as the effect of texture on hardness values. For the studied coatings, the hardness is in the range of 20-25 GPa. The presence of texture [311] in CrN/MoN nanocomposite coatings leads to the lowest friction coefficient with a value of about 0.2.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 A study of an effect of the parameters of niobium-based ion cleaning of a surface on its structure and properties(PC тесhnology сеntеr, 2017) Postelnyk, H. O.; Knyazev, S.; Meylekhov, A. A.; Stolbovoy, V. A.; Kovteba, D. V.The paper describes using techniques of structural engineering in a comprehensive study of the effects of the negative displacement potential, nitrogen and argon pressures, as well as the distance from a sample to the cathode on the processes of sputtering and depositing. In practice, it is highly important to obtain steel surfaces with high mechanical properties and low roughness. The highest microhardness is manifested at the highest degree of sputtering on the samples at Ub=–1,300 V. It has been determined that the presence of nitrogen in the vacuum chamber shifts the equilibrium point of sputtering and depositing towards a higher Ub. It has been established that the presence of argon in the ion bombardment process increases the sputtering rate, whereas the presence of active nitrogen gas reduces the deposition rate due to nitride formations on the surface. The point “sputtering-depositing” shifts: in the case of Ar (from Ub=–350 V to Ub=–200...–300 V) when the RN increases from 0.002 Pa to 0.66 Pa, respectively. In the case of nitrogen, when PN increase from 0.02 Pa to 0.08 Pa, the point shifts from Ub=–400 V to Ub=–600 V (at a distance of 300 mm from the cathode to the sample).Документ Вплив величини потенціалу зсуву на структурну інженерію вакуумно-дугових покриттів на основі ZrN(Прикарпатський національний університет імені Василя Стефаника, 2021) Соболь, Олег Валентинович; Постельник, Ганна Олександрівна; Пінчук, Наталія Володимирівна; Мейлехов, Андрій Олександрович; Жадко, М. О.; Андреєв, А. О.; Столбовий, Вячеслав ОлександровичСтворення наукових основ структурної інженерії надтонких наношарів в багатошарових нанокомпозитах є основою сучасних технологій формування матеріалів з унікальними функціональними властивостями. Показано, що збільшення від’ємного потенціалу зсуву (від -70 до -220 В), при формуванні вакуумно-дугових нанокомпозитів на основі ZrN, дозволяє не тільки управляти переважною орієнтацією кристалітів і субструктурними характеристиками, але і змінює умови сполучення кристалічних решіток в надтонких (близько 8 нм) наношарах.Документ Influence of Bias Potential Magnitude on Structural Engineering of ZrN-Based Vacuum-Arc Coatings(Vasyl Stefanyk Precarpathian National University, 2021) Sobol, O. V.; Postelnyk, H. O.; Pinchuk, N. V.; Meylekhov, A. A.; Zhadko, M. A.; Andreev, A. A.; Stolbovoy, V. A.The creation of the scientific foundations for the structural engineering of ultrathin nanolayers in multilayer nanocomposites is the basis of modern technologies for the formation of materials with unique functional properties. It is shown that an increase in the negative bias potential (from -70 to -220 V) during the formation of vacuum-arc nanocomposites based on ZrN makes it possible not only to control the preferred orientation of crystallites and substructural characteristics, but also changes the conditions for conjugation of crystal lattices in ultrafine (about 8 nm) nanolayers.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 Structure, Adhesion Strength and Corrosion Resistance of Vacuum Arc Multi-Period NbN/Cu Coatings(2020) Postelnyk, H. O.; Sobol, O. V.; Chocholaty, O.; Zelenskaya, G. I.The influence of deposition modes on the phase-structural state, corrosion resistance, and adhesive strength of vacuum-arc multi-period NbN/Cu coatings is studied. It was found that in thin layers (about 8 nm, in a constant rotation mode), regardless of the change in the pressure of the nitrogen atmosphere, a metastable δ - NbN phase forms (cubic crystal lattice of the NaCl type). At a layer thickness of ~ 40 nm or more, a phase composition changes from the metastable δ - NbN to the equilibrium ε - NbN phase with a hexagonal crystal lattice. In the presence of the ε - NbN phase in the niobium nitride layers, the highest adhesive strength is achieved with a value of LС5 = 96.5 N. Corrosion resistance tests have shown that for all the studied samples the corrosion process has mainly an anodic reaction. The highest corrosion resistance was shown by coatings obtained at a pressure of 7·10-4 Torr, with the smallest bias potential of -50 V and the smallest layer thickness; with a thickness of such a coating of about 10 microns, its service life in the environment of the formation of chloride ions is about a year.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.