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Документ ANN simulation of nanocomposites Fe(Co)-W corrosion resistance(Харківський національний університет міського господарства імені О. М. Бекетова, 2019) Ved, M. V.; Sakhnenko, N. D.; Nenastina, T. A.; Volobuyev, M. N.; Yar-Muhamedova, G. H.Документ Galvanochemical formation of functional coatings by the cobalt-tungsten-zirconium alloys(Institute for Single Crystals, 2020) Nenastina, T. A.; Ved, M. V.; Sakhnenko, N. D.; Proskurina, V. O.; Fomina, L. P.The functional properties of ternary Co-W-Zr(ZrO₂) alloys obtained in a pulsed mode from pyrophosphate-citrate electrolytes are discussed. The obtained coatings are characterized by a uniformly developed surface without cracks and a sufficiently high and reproducible microhardness. It was determined that the size of the globules on the alloy surface decreases with increasing of the current density to 10 A/dm². It was found that increase of temperature favorably affects the current efficiency of the alloy and the microhardness of the Co-W-Zr(ZrO₂) coating. The modes of electrosynthesis of the coatings by cobalt-tungsten-zirconium alloys are substantiated, an their influence on the functional properties of the alloy and current efficiency is investigated.Документ Nanocomposite electrolytic coatings based on cobalt alloys with refractory metals: obtaining, properties, application(Kazakh University IP "Center for Operational Printing", 2022) Yar-Mukhamedova, G. Sh.; Nenastina, T. A.; Ved, M. V.; Sakhnenko, N. D.; Karakurkchi, A. V.Modern electrochemical technologies for surface treatment of titanium alloys to create protective, antifriction, dielectric, and catalytically active materials are considered. The physicochemical fundamentals of the processes of plasma-electro-lytic formation of conversion and composite electrolytic coatings are highlighted. Separate stages of electrode reactions, regularities of the influence of electrolyte components, and electrolysis parameters on the composition, structure, and morphology of synthesized materials are examined in detail. Considerable attention is paid to improving the synthesis of multicomponent alloys and composites based on cobalt from aggregative stable and stable electrolyte solutions, and flexible control of the composition and functional properties of materials is an urgent scientific and technical problem, the solution of which is the presented study. The monograph summarizes the results of the project AP 08855457, "Development of an innovative technology for producing nanocrystalline composite coatings for fuel cell electrodes and hydrogen energy". This research has been funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan. The monograph is designed for specialists in the field of chemical technology, as well as teachers, graduate students, and students of higher educational institutions.Документ Сorrosion behavior of the electrolytic ternary cobalt alloys with Mo(W) and Zr in alkaline solution(Інститут загальної та неорганічної хімії ім. В. І. Вернадського, 2019) Nenastina, T. A.; Ved, M. V.; Sakhnenko, N. D.; Yermolenko, I. Yu.; Proskurina, V. A.; Volobuyev, M. M.The ternary Co–Mo–W(Zr) coatings with total content of refractory metals of 30–40 wt.%, and Co–W–Zr alloys (12–26 wt.%) are deposited from pyrophosphate-citrate electrolytes in pulse regime. The composition of the coatings as well as the surface morphology depends on the current density. The X-ray diffraction patterns reflect the amorphous-and-crystalline ternary alloys structure. Phases of α-Co, Co–Mo intermetallic compounds, and traces of metallic molybdenum were detected in the Co–Mo–Zr coatings. Phase composition of Co–Mo–W deposits differs by emergence of Co₇W₆ phase and traces of metallic tungsten, and there is no metallic W in Co–W–Zr electrolytic alloys. The corrosion behavior of ternary coatings in alkaline medium studied by EIS shows that Co–Mo–Zr alloys are characterized by highest corrosion resistance among deposited coatings due to presence of metallic molybdenum and stoichiometric ZrO₂ with both high electrical resistivity and chemical stability. The coatings Co–Mo–W and Co–Mo–Zr containing phases of Mo or W are characterized by higher corrosion resistance as compared with that without metallic molybdenum and tungsten. The cyclic voltammetry data confirm stability of ternary coatings in alkaline solution under anodic polarization. Such properties as well as the developed globular surface make materials promising for use as anodes in fuel cells in particular based on alkali electrolytes.Документ Cobalt based coatings as catalysts for methanol oxidation(Науково-технологічний комплекс "Інститут монокристалів", 2020) Nenastina, T. A.; Ved, M. V.; Sakhnenko, N. D.; Yermolenko, I. Yu.; Volobuyev, M.; Proskurina, V. O.The cobalt based coatings with refractory metals (Mo, W, Zr) were deposited from pyrophosphate-citrate electrolytes in a pulsed mode. It has been shown that, with increasing current density, Co-Mo-W and Co-W-ZrO2 alloys are enriched in tungsten, grain sizes decrease, but a network of cracks appears on the surface of the Co-Mo-W coating. In the Co-Mo-ZrO2 coating, with increasing current density, the zirconium content increases due to molybdenum, and the surface is the most fractured and small-globular. The surface roughness parameters for Co-Mo-ZrO2 are one order of magnitude higher than those for Co-Mo-W. Cyclic voltammograms show that the Co-Mo-ZrO2 deposits are characterized by the highest stability under anodic polarization due to the inclusion of molybdenum and zirconium(IV) oxide in their composition. The kinetics of the methanol anodic oxidation on electrodes coated with cobalt alloys was studied, and the participation of intermediate metal oxides in oxygen transport was revealed. A significant increase in the anode current peak indicates a higher electro-catalytic activity of the zirconium-containing coatings among the studied alloys.Документ Functional coatings of ternary alloys of cobalt with refractory metals(Pleiades Publishing, 2015) Sakhnenko, N. D.; Ved, M. V.; Hapon, Yu. K.; Nenastina, T. A.Finely crystalline cobalt–molybdenum–tungsten coatings were deposited in the nonsteady-state mode from a polyligand citrate-pyrophosphate electrolyte at a concentration ratio of the alloy-forming components Со²⁺ / (WO₄²⁻ + MoO₄²⁻) = 1 : 1 and citrate/pyrophosphate ligands of 1 : 2. It was found that the quantitative composition and current efficiency by the ternary alloy depends on the current density. The effect of energy and time-related parameters of the pulsed electrolysis on the surface morphology and roughness was studied. It was shown that, as the total content of refractory metals in Co–Mo–W coatings increases, the corrosion rate decreases in the acid medium and increases in the alkaline medium because of the instability of molybdenum and tungsten oxides.