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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 Corrosion properties of galvanic Fe–Mo(W), Fe–Mo–W coatings(Науково-технологічний комплекс "Інститут монокристалів", 2019) Ved, M. V.; Sakhnenko, N. D.; Karakurkchi, A. V.; Pershina, K. D.; Yermolenko, I. Yu.The methods of analysis of polarization dependences, the electrode impedance spectroscopy and gravimetry were used for the investigation of the corrosion properties of galvanic binary Fe–Mo(W) and ternary Fe–Mo–W coatings in the media of a different acidity. It was shown that the corrosion rate of Fe–Mo–W and Fe–Mo(W) alloys is decreased with an increase in the pH of the solutions and with the enrichment of the alloys by doping refractory components. The dependence of the control of corrosion process on the composition of electrolytic alloys has been specified. It was established that the corrosion resistance of binary alloys is 1.1 to 1.5 orders of magnitude higher in comparison with the parameters of substrate materials, in particular the mild steel. The corrosion resistance indices for the coatings applied using the ternary Fe–Mo–W alloys substantially prevail over those for mild steel, individual metals and binary Fe–Mo and Fe–W coatings. The corrosion resistance of Fe–Mo–W system is equal to 8300 Ohm·cm² and it is conditioned by the formation of the two-component layer film consisting of molybdenum oxides and tungsten oxides. Using the data of gravimetric investigations we constructed the diagrams "the corrosion depth index kh, mm/year – the composition" for the Fe–Mo–W system that allow us to define the metal content ratio for Fe–Mo(W), Fe–Mo–W alloys in order to provide an appropriate corrosion resistance depending on service conditions.Документ Influence of alloying elements on corrosion-mechanic properties of multi-component electrolytic alloys(2018) Ved, M. V.; Yermolenko, I. Yu.; Nenastina, T. O.; Ziubanova, SvitlanaДосліджено кількісний і фазовий склад покривів тернарними сплавами Fe-Co-Mo(W) та Co-Mo-W(Zr), осаджених з моно і білігандних електролітів постійним та імпульсним струмом. Результати рентгеноструктурного аналізу свідчать про аморфно-кристалічну структуру сплавів, наявність фаз інтерметалідів Fe7Мо, Fe7Co, FeCo, Co7W6, Fe7W6, разом із α-Fe та Fe3C, причому розміри кристалітів аморфної частини знаходяться в інтервалі 7–8 нм. Методом сканівної електронної спектроскопії, атомно-силової мікроскопії і рентгеноспектрального мікроаналізу встановлено вплив природи та вмісту тугоплавких і рідкісних металів на морфологію, шорсткість поверхні покривів, а також розміри кристалітів і агломератів. Методом поляризаційного опору встановлено, що корозійна стійкість покривів на 1,3–2,0 порядки величини вища за параметри матеріалу підкладки. Визначено залежність швидкості корозійного процесу у хлоридвмісному середовищі від складу електролітичних сплавів. За даними спектроскопії електродного імпедансу встановлено еквівалентні схеми заміщення, їх параметри і доведено тотожність показників корозійного опору, одержаних різними методами. Проаналізовано вплив складу і морфології поверхні на мікротвердість електролітичних сплавів. Показано, що за фізико-механічними характеристиками тернарні покриви Fe-Co-Mo(W), Co-Mo-W(Zr) не поступаються електролітичним покривам твердим хромом.Документ Functional Properties of Fe−Mo and Fe−Mo−W Galvanic Alloys(Springer, Heidelberg, Allemagne, 2016) Ved, M. V.; Sakhnenko, N. D.; Karakurkchi, G. V.; Yermolenko, I. Yu.; Fomina, L. P.The influence of the modes of electrodeposition on the morphology, topography, and structure of the galvanic alloys of iron with molybdenum and tungsten is discussed. It is shown that the increase in the corrosion resistance of Fe–Mo and Fe–Mo–W coatings in acid and neutral chloride-containing media is caused both by the elevation of their passivating ability caused by the process of alloying components and by the formation of globular surfaces with homogeneous chemical composition. The microhardnesses of Fe–Mo and Fe–Mo–W galvanic alloys prove to be 2–3 times higher than the microhardnesses of the substrates made of low-alloy steel, which can be explained by the formation of amorphous structures. The results of investigations and tribological tests show that it is reasonable to apply the coatings of double and triple iron alloys in order to reduce wear in friction couples and to increase the corrosion resistance and mechanical strength of the surfaces, which makes them promising for the repair and restoration technologies.Документ Electroplating and functional properties of Fe-Mo and Fe-Mo-W coatings(Украинский государственный химико-технологический университет, 2014) Ved, M. V.; Sakhnenko, N. D.; Karakurkchi, A. V.; Yermolenko, I. Yu.Peculiarities of electrodeposition Fe-Mo and Fe-Mo-W coatings from citrate bath containing iron (III) on substrates of mild steel and cast iron are investigated. The utilization of iron (III) compounds significantly enhanced the stability and service life of electrolyte due to elimination redox reactions involving complexing and side anodic reactions. The effect of alloying components salt concentration and electrolysis mode on the quality, composition and properties of the alloys were determined. It is shown that alloys formed in nonstationary electrolysis have a uniform surface, composition and a lower content of impurities. Increased physical and mechanical properties as well as corrosion resistance of Fe-Mo and Fe-Mo-W coatings compared with the base metal are caused by the presence of propensity for passivation alloying components as well as by amorphous structure of electroplating alloys. Indicated coatings can be considered as promising in surface hardening technologies and repair of of worn items.Документ Functional properties of multicomponent galvanic alloys of iron with molybdenum and tungsten(Institute for Single Crystals, 2015) Karakurkchi, A. V.; Ved, M. V.; Sakhnenko, N. D.; Yermolenko, I. Yu.; Zyubanova, S. I.; Kolupayeva, Z. I.Galvanic alloy coatings Fe-Mo (W) and Fe-Mo-W were deposited from citrate bath based on Fe (III) using both direct and pulsed current on substrates steel 3 and grey cast iron GC 18. It was shown that the alloying components content, their distribution on the surface, morphology and topography of the coatings are depended on the electrolysis mode. It was established that the functional properties of the binary and ternary alloys of iron (corrosion resistance, microhardness, antifriction et al.) exceed parameters of the substrate and are predetermined by the composition, structure, material and surface roughness.Документ Iron binary and ternary coatings with molybdenum and tungsten(Elsevier Inc., 2016) Ved, M.; Sakhnenko, N. D.; Karakurkchi, A.; Yermolenko, I. Yu.; Yar-Mukhamedova, G.Electrodeposition of Fe-Mo-W and Fe-Mo layers from a citrate solution containing iron(III) on steel and iron substrates is compared. The utilization of iron(III) compounds significantly improved the electrolyte stability eliminating side anodic redox reactions. The influence of concentration ratios and electrodeposition mode on quality, chemical composition, and functional properties of the alloys is determined. It has been found that alloys deposited in pulse mode have more uniform surface morphology and chemical composition and contain less impurities. Improvement in physical and mechanical properties as well as corrosion resistance of Fe-Mo and Fe-Mo-W deposits when compared with main alloy forming metals is driven by alloying components chemical passivity as well as by alloys amorphous structure. Indicated deposits can be considered promising materials in surface hardening technologies and repair of worn out items.