Browsing by Author "Tytarenko, Valentyna V."
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Item Adhesion Strength of Electrodeposited Ni, Zn, and Fe Coatings with Copper Substrates(Taylor & Francis Online, 2022) Shtapenko, Eduard Ph.; Zabludovsky, Vladimir A.; Tytarenko, Valentyna V.ENG: This paper presents the adhesive strength values of electrodeposited nickel, zinc, and iron coatings on copper substrates at various deposition parameters, including laser-assisted stimulation of the deposition process. One of the factors determined to be responsible for the adhesive strength of metal films with a metal substrate is the formation of a diffusion zone at the ‘coating-substrate’ interface. It is shown that an increase in adhesive strength is achieved due to the expansion of the diffusion zone and the formation of solid solutions. The decrease in adhesive strength at high overpotentials is associated with the release of hydrogen and the formation of intermediate phases.Item Application of Pulse Current for Producing a Strengthening Composite Nickel Coating(Eugen G. Leuze Verlag, 2019) Tytarenko, Valentyna V.; Zabludovsky, Vladimir A.; Shtapenko, Eduard P.; Tytarenko, Igor V.EN: Carbon-containing nickel coatings deposited with use of pulse current from aqueous electrolyte solution comprising ultradispersed diamond particles were studied. Effect of pulse current on concentration and distribution of co-deposited nanodiamond particles through a metal substrate matrix, structure, mechanical and resistance properties of composite electrolytic coatings was analyzed. It was demonstrated that application of new generation additives, more specifically nanocarbon ones, provides opportunity for improving physicochemical properties of coatings. During pulse mode of deposition fine-grained coatings are formed with microlayer growth structure in cross section that enhance their microhardness, wear strength and corrosion resistance.Item Kinetic Regularities of the Formation of Composite Electrolytic Coatings Containing Ultradispersed Diamond Particles(Vasyl Stefanyk Precarpathian National University, Ukraine, 2022) Tytarenko, Valentyna V.; Zabludovsky, Vladimir A.; Shtapenko, Eduard Ph.; Tytarenko, Igor V.ENG: The paper formulates the problem of joint electrolytic co-deposition of metal ions and ultradispersed diamond particles into a metal matrix. It presents the developed mathematical model that describes the mechanism and kinetics of the cathode process, mass transfer of metal ions and ultradispersed diamond particles. A satisfactory correlation with experimental data was obtained. The contribution of the thermal action of laser radiation to the intensification of the process of co-deposition of dispersed particles and metal ions was determined. It was found that the more intense penetration of dispersed phase particles into the forming coating during the laser stimulation of the electrodeposition process is due to the presence of a temperature gradient, which provides an additional supply of metal ions in the irradiation region. Based on the theoretical and experimental studies, we established the regularities of the influence of the number and size of nanoparticles on the strengthening properties of composite metal coatings. It was found that an increase in the temperature of an aqueous electrolyte solution in the cathode region during a laser-stimulated deposition process leads to an increase in the flux density of ultradispersed diamond particles, and, as a result, to an increase in the concentration of the dispersed phase in nickel composite coatings, which contributes to the formation of a finer crystalline structure of coatings, an improvement in adhesion, strength properties and increased wear resistance of coatings.Item Laser-Enhanced Electrodeposition of Nickel Coatings(Taylor & Francis Group, London, 2017) Zabludovsky, Vladimir A.; Tytarenko, Valentyna V.; Shtapenko, Eduard P.EN: A method for producing the composite nickel coatings with a programmable pulse current with the changing from one layer to the concentration of particles in the metallic matrix of nanodiamonds. It is shown that this program allows layer-coating with the lowest concentration of nanodiamond in the first coating layers and increasing in subsequent layers, which improves adhesive properties, increases wear resistance and lowers the cost of dispersed particles of nanodiamond.Item Quantum Mechanical Approach for Determining the Activation Energy of Surface Diffusion(Физико-технический институт им. А.Ф. Иоффе Российской академии наук, Санкт-Петербург, 2020) Shtapenko, Eduard P.; Tytarenko, Valentyna V.; Zabludovsky, Volodymyr O.; Voronkov, Eugene O.EN: A quantum mechanical approach was proposed to determine the activation energy of surface diffusion for copper, nickel, zinc and iron atoms adsorbed on a copper substrate during electrocrystallization for various overvoltages of the substrate. The activation energy of surface diffusion was calculated from the crystal total energy. An increase in the activation energy of surface diffusion with increasing surface potential is associated with an increase in the binding energy between the ad-atom and the substrate.Item Quantum-Mechanical Modeling of the Interaction between Carbon Nanostructures and Metal Ions(Pleiades Publishing, Ltd, 2021) Tytarenko, Valentyna V.; Shtapenko, Eduard P.; Voronkov, Eugene O.; Zabludovsky, Volodymyr O.; Kolodziejczyk, Wojciech; Kapusta, Karina; Kuznetsov, Vitaliy N.EN: In order to investigate a deposition mechanism, authors have proposed a set of quantum chemical models for formation of fullerene C60 and single-wall carbon nanotubes (SWNTs) C48 metal complexes with Co, Ni, Cu, and Zn. Obtained results proving that adsorption of Co, Ni, Cu, Zn ions on a surface of fullerene C60 and SWNT C48 from the aqueous solution of electrolytes is possible with formation of stable metal-doped carbon nanoparticle complexes. Minimum energy complexes of C60-Co and C60-Cu have corresponded to the structure where ion is located above the center of C6 cell. Meanwhile, C60-Ni complex reach a minimum energy when ion is above the middle of a C-C bond, and for C60-Zn complex the most stable conformation is the one when ion is upon the carbon atom. All the optimized structure for metal complexes with C48 has shown ions been located above the C6 cell’s center.Item Structure and Properties of Composite Nickel Coatings Deposited by Means of Programmable Pulsed Current under Laser Irradiation(Pleiades Publishing, 2019) Tytarenko, Valentyna V.; Zabludovsky, Volodymyr O.; Shtapenko, Eduard P.EN: A method for the formation of composite electrolytic coatings in the process of electrodeposition in an electrolyte with ultradisperse diamond (UDD) particles in the programmable pulsed current regime under simultaneous laser irradiation has been developed. This method provides the layer-by-layer deposition of gradient nickel coatings 15–20 μm in thickness with a variable content of UDD particles along their depth. The amount of UDD particles is minimal (0.10–0.13 at %) in the layers deposited in the initial period of this process, whereas the concentration of UDD particles in the layers formed at the later process stages grows to 0.19–0.26 at %. The concentration gradient of UDD particles along the depth improves the adhesion properties and wear resistance of coatings and provides a 16% decrease in the consumption of UDD particles with a local increase in the concentration of UDD particles in a coating to 0.32 at %.