Факультет електроніки та інформаційних технологій (ЕлІТ)
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Item Specific Features of the Microstructure and Properties of Multielement Nitride Coatings Based on TiZrNbAlYCr(Pleiades Publishing, Ltd., 2018) Погребняк, Олександр Дмитрович; Погребняк, Александр Дмитриевич; Pohrebniak, Oleksandr Dmytrovych; Бондар, Олександр В`ячеславович; Бондарь, Александр Вячеславович; Bondar, Oleksandr Viacheslavovych; Кравченко, Ярослав Олегович; Кравченко, Ярослав Олегович; Kravchenko, Yaroslav Olehovych; Beresnev, V.M.; Zhollybekov, B; Kupchishin, A.I.Multicomponent nanostructured coatings based on (TiZrNbAlYCr)N with a hardness as high as 47 GPa were obtained by cathodic arc deposition. The effect of partial nitrogen pressure PN (with constant bias potential Ub = –200 V applied to the substrate) on the phase-composition variation, the size of crystallites, and their relation to the microstructure and hardness was investigated. An increase in the nitrogen pressure resulted in the formation of two phases with characteristic BCC (the lattice period is 0.342 nm) and FCC lattices with averaged nanocrystallite sizes of 15 and 2 nm. At a high pressure of 0.5 Pa, crystallites in the FCC phase with a lattice period of 0.437 nm grew in size to ~7 nm. The hardness of deposited coatings with larger (3.5 nm) FCC-phase crystallites and smaller (7 nm) BCC-phase crystallites was enhanced considerablyItem Structure and Physicomechanical Properties of Nanostructured (TiHfZrNbVTa)N Coatings after Implantation of High Fluences of N+ (1018 cm−2)(Polish Academy of Science, Institute of Physics, 2017) Погребняк, Олександр Дмитрович; Погребняк, Александр Дмитриевич; Pohrebniak, Oleksandr Dmytrovych; Бондар, Олександр В`ячеславович; Бондарь, Александр Вячеславович; Bondar, Oleksandr Viacheslavovych; Борьба, Світлана Олександрівна; Борьба, Светлана Александровна; Borba, Svitlana Oleksandrivna; Piotrowska, K.; Boiko, O.New classes of high-entropy alloys, which consist of at least 5 main elements with atomic concentrations 5– 35 at.%, are under great interest in modern material science. It is also very important to explore the limits of resistance of high-entropy alloy nitrides to implantation by high-energy atoms. Structure and properties of na- nostructured multicomponent (TiHfZrNbVTa)N coatings were investigated before and after ion implantation. We used the Rutherford backscattering, scanning electron microscopy with energy dispersive X-ray spectroscopy, high resolution transmission electron microscopy and scanning transmission electron microscopy with local microanalysis, X-ray diffraction and nanoindentation for investigations. Due to the high-fluence ion implantation (N+, the fluence was 1018 cm−2) a multiphase structure was formed in the surface layer of the coating. This structure consisted of amorphous, nanocrystalline and initial nanostructured phases with small sizes of nanograins. Two phases were formed in the depth of the coating: fcc and hcp (with a small volume fraction). Nitrogen concentration reached 90 at.% near the surface and decreased with the depth. Nanohardness of the as-deposited coatings varied from 27 to 34 GPa depending on the deposition conditions. However, hardness decreased to a value of 12 GPa of the depth of the projected range after ion implantation and increased to 23 GPa for deeper layers.Item Influence of deposition parameters on the structure and properties of nitride coatings(One Central Press, 2014) Погребняк, Олександр Дмитрович; Погребняк, Александр Дмитриевич; Pohrebniak, Oleksandr Dmytrovych; Azarenkov, N.A.; Beresnev, V.M; Litovchenko, S.V.High-entropy alloys (HEAs) – are multicomponent alloys containing five or more principal elements, mixed in equiatomic ratios [1]. The main difference between conventional multi-component alloys and HEAs is that HEAs don’t have a dominant principle element; and this concept is a breakthrough in the field of alloys development [2-10]. Phase composition investigations of high-entropy alloys evidence, that predominantly only one solid-solution phase with fcc and/or bcc lattice, or amorphous phase is formed in HEAs. Formation of the various phases is not observed. Such structural stability promotes improves the physical and mechanical characteristics of HEAs. Various nitrides ([11-19]) and carbides [20] based on high-entropy were investigated. High mechanical hardness and Young modulus, high durability and corrosion resistance, thermal stability make highentropy alloys one of the promising and interesting materials in science.Item Influence of residual pressure and ion implantation on the structure, elemental composition, and properties of (TiZrAlYNb)N nitrides(Pleiades Publishing, Ltd, 2015) Погребняк, Олександр Дмитрович; Погребняк, Александр Дмитриевич; Pohrebniak, Oleksandr Dmytrovych; Yakushchenko, I. V.; Sobol, O. V.; Beresnev, V. M.; Бондар, Олександр В`ячеславович; Бондарь, Александр Вячеславович; Bondar, Oleksandr Viacheslavovych; Kupchishin, A. I.; Lisovenko, M.A.; Amekura, H.; Kono, K.; Oyoshi, K.; Takeda, Y.The nitrides of highentropy alloys, (TiZrAlYNb)N, fabricated by cathodic vacuum arc evaporation are studied with electron microscopy, atomic force microscopy, laser scanning microscopy; energydispersive Xray analysis, Xray phase analysis, timeofflight secondaryion mass spectrometry; and hardness measurements. It is found that the deposition parameters influence the structure, surface morphology, element distribution, and mechanical properties. The structural–phase state of the coatings before and after the ion implantation of heavy negative gold ions Au– are compared. DOI: 10.Item Структура и свойства высокоэнтропийных сплавов и нитридных покрытий на их основе(Российская академия наук, Институт органической химии им. Н.Д. Зелинского, 2014) Погребняк, Олександр Дмитрович; Погребняк, Александр Дмитриевич; Pohrebniak, Oleksandr Dmytrovych; Багдасарян, Артем Анатолійович; Багдасарян, Артем Анатольевич; Bahdasarian, Artem Anatoliiovych; Якущенко, И.В.; Береснев, В.М.Проанализированы и обобщены результаты исследований закономерностей формирования структуры и свойств высокоэнтропийных сплавов в зависимости от методов их получения. Рассмотрены особенности синтеза нитридных покрытий на основе многокомпонентных сплавов. Проведен сравнительный анализ основных физико-механических характеристик таких покрытий в зависимости от параметров осаждения и элементного сплава.