Факультет електроніки та інформаційних технологій (ЕлІТ)
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Item Mechanical and tribological characterization of nanostructured HfB2 flms deposited from compound target(Springer Nature, 2020) Буранич, Володимир Володимирович; Буранич, Владимир Владимирович; Buranych, Volodymyr Volodymyrovych; Погребняк, Олександр Дмитрович; Погребняк, Александр Дмитриевич; Pohrebniak, Oleksandr Dmytrovych; Budzynski, P.; Шелест, Ігор Владиславович; Шелест, Игорь Владиславович; Shelest, Ihor Vladyslavovych; Prószyński, A.; Chocyk, D.; Гончаренко, Олексій Сергійович; Гончаренко, Алексей Сергеевич; Honcharenko, Oleksii Serhiiovych; Юнда, Андрій Миколайович; Юнда, Андрей Николаевич; Yunda, Andrii MykolaiovychFabrication and development of HfB2-based nanostructured coatings was investigated. All flms were deposited on stainless-steel substrates by RF magnetron sputtering from stochiometric HfB2 target in argon atmosphere. The aim of this work is to evaluate the efects of the bias potential on the microstructure, mechanical and tribological properties. These parameters strongly depend on the experimental conditions. X-ray difraction analysis indicated the diference in microstructure: from dense hexagonal structure with (0001) preferred orientation of nanocrystallites to quasi-amorphous with blurred HfB2 phase peaks. All coatings were measured using nanoindentation (using Berkovich tip), tribology (ballon-disk) and nano-scratch (friction). Coatings with a thickness of 1–2 µm had a signifcant dependence of properties on the microstructure: hardness drastically increased from 8 to 45 GPa, H/E ratio and elastic recovery changed respectively: 0.04–0.15 and 0.26–0.72.Item The cathodic electrolytic plasma hardening of the 20Cr2Ni4A chromium-nickel steel(Elsevier, 2020) Rakhadilov, B.K.; Буранич, Володимир Володимирович; Буранич, Владимир Владимирович; Buranych, Volodymyr Volodymyrovych; Satbayeva, Z.A.; Sagdoldina, Z.B.; Kozhanova, R.S.; Погребняк, Олександр Дмитрович; Погребняк, Александр Дмитриевич; Pohrebniak, Oleksandr DmytrovychIn order to obtain the modified surface structure of the 20Cr2Ni4A steel plasma electrolytic hardening (PEH) method was used. The surface hardening process was conducted in the aqueous electrolyte solution of 20% sodium carbonate and 20% urea. The sample consists of a ferritic-pearlitic structure, i.e. the part retains its viscous core, and the surface layer contains carbide particles. Hardening process induces martensite transformation and creation of carbide particles in the surface layer. The presence of carbide particles in the surface layers has a positive effect on the tribo-mechanical performance. Hardened structure 600 m long was obtained with hardness increase up to 520 HV and 2.5 times higher wear resistance. Tribological test results showed the difference of the coefficient of friction as a function of surface roughness determined by plasma-electrolytic hardening process.Item Irradiation resistance, microstructure and mechanical properties of nanostructured (TiZrHfVNbTa)N coatings(Elsevier, 2016) Погребняк, Олександр Дмитрович; Погребняк, Александр Дмитриевич; Pohrebniak, Oleksandr Dmytrovych; Yakushchenko, I.V.; Beresnev, V.M.; Oyoshi, K.; Ivasishin, O.M.; Amekura, H.; Takeda, Y.; Opielak, M.; Kozak, C.; Бондар, Олександр В`ячеславович; Бондарь, Александр Вячеславович; Bondar, Oleksandr ViacheslavovychNitrides of high-entropy alloys (TiHfZrNbVTa)N were fabricated using cathodic-vacuum-arc-vapor deposition method. Morphology and topology of the surface of the coatings, roughness, elemental and phase composition, microstructure and mechanical properties were investigated. Dependence of deposition parameters on surface morphology and elemental composition was demonstrated. Influence of the heavy negative charged Au ions implantation on phase structure, microstructure and hardness of nitride (TiHfZrNbVTa)N coatings was investigated.Item Obtaining of TiN/MoN Nanocomposite Coatings and Their Research(Sumy State University, 2013) Погребняк, Олександр Дмитрович; Погребняк, Александр Дмитриевич; Pohrebniak, Oleksandr Dmytrovych; Бондар, Олександр В`ячеславович; Бондарь, Александр Вячеславович; Bondar, Oleksandr Viacheslavovych; Постольний, Богдан Олександрович; Постольный, Богдан Александрович; Postolnyi, Bohdan Oleksandrovych; Abadias, G.; Andreev, A.A.; Beresnev, V.M.; Chartier, P.; Sobol, O.V.; Maksakova, O.At the nanometer scale multilayer nanostructured coatings show special properties due to the depositions conditions. This paper presents results of TiN/MoN nanocomposites obtaining and their research. Multilayer coatings based on TiN/MoN were deposited using vacuum arc evaporation cathode method (CPVD). Total thickness range of obtained coatings was 2, 10, 20 and 40 nm. We used vacuum-arc device “Bulat-6” for coatings deposition. Structure and properties of multilayer coatings were analyzed using XRD (Bruker D-8 Advance) in Cu-Kα radiation, high resolution transmission electron microscopy (HRTEM system) with diffraction CFEI EO Techai F200, SEM with EDX (JEOL-7001F). Scratch tests were carried out using Rockwell-C diamond indenter (CSM Revetest Instruments) with a tip radius of 200 μm. Besides this, ball-on-plate sliding test on UMT-3MT tribometer (CETR, USA) was used for additional investigation of friction and wear. This research allowed to reveal structural and properties depending on deposition conditions of TiN/MoN multilayer coatings. The nanocomposite hardness value increases when monolayer thickness decreases. This also reduced nanograins size. Measurement of the friction coefficient demonstrates smaller values for multilayer system in comparison with TiN or MoN nanostructured coatings. Formation of a (Ti, Mo)N solid solution and nanocrystals growing were observed during annealing. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35415Item Investigation of element profiles, defects, зhase composition and physical and mechanical properties of superhard coatings Ti-Hf-Si-N(Scientific Research, 2013) Погребняк, Олександр Дмитрович; Погребняк, Александр Дмитриевич; Pohrebniak, Oleksandr DmytrovychThis paper investigates the microstructure, physical, chemical and mechanical of superhard nanocomposite of Ti-Hf-Si-N. The coatings were grown by C-PVD method. Profiles of elements and vacancy-type defects (S-parameter measurements of the Doppler broadening of the annihilation peak DBAP) in the studied coatings were investigated. Defined and calculated the elastic modulus E, hardness H, friction, adhesion. Wear rate was determined as a function of the bias potential supplied to the substrate and the pressure in the chamber. The developed coatings have hardness of 37.8 to 48 GPa, the friction coefficient of 0.48 to 0.15, the grain size of the solid solution from 3.9 to 10.8 nm (depending on deposition conditions). It was found that positrons are trapped by defects at the junction of three or more nanograins interfaces. In some cases, there was formed two phases in coatings: a solid solution (Ti, Hf)N with different volume content of Hf in a solid solution, and an amorphous phase α-Si3N4 (the layer between the nanograins). When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/33950Item Changing of defect’s structure and properties of superhard nanostructured Ti-Si-N coatings, fabricated using CPVD, before and after annealing(Scientific Research, 2013) Погребняк, Олександр Дмитрович; Погребняк, Александр Дмитриевич; Pohrebniak, Oleksandr Dmytrovych; Бондар, Олександр В`ячеславович; Бондарь, Александр Вячеславович; Bondarenko, Oleksandr Viacheslavovych; Соболь, О.В.; Sobol, O.V.; Береснев, В.М.; Beresnev, V.M.Using such unique methods of analysis as slow positron beam (SPB), RBS, μ-PIXE (proton microbeam), XRD, SEM with EDS, XPS, nanohardness and elastic modulus measurements, we studied superhard nanostructure Ti-Si-N coatings, which were deposited using Cathodic-PVD method, before and after annealing at the temperature of 600°C for 30 minutes. It is shown in the paper that redistribution of N and Si occurs on the borders of nanograins after annealing, amorphous phase α-SiNx (Si3N4) is created, defects segregates on interfaces and forms vacancy-type clusters with rather high concentration from 5 × 10[16] cm-3 to 7.5 × 10[17] cm-3 due to thermodiffusion. Solid solution (Ti,Si)N and small concentration of α-SiN (close to XRD detection limits) are formed in the coating. Also it was obtained, that deflected mode is formed in the coating (compressive deformation equals to –2.6%), but after thermal annealing deformation reduces to a value of -2.3%. Size of nanograins of solid solution (Ti, Si)N increases from 12.5 nm to (13.2 ÷ 13.4) nm. 25 nm size grains increase their size to 28.5 nm after annealing (under another deposition regime). When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/33948