Кафедра "Технічна електрохімія"

Зараз показуємо 1 - 3 з 3

Studying the insulating properties of oxide films obtained on the TI6A14V alloy in tartaric acid solutions using the method of electrochemical decoration by copper
(2020) Pilipenko, A. I.; Smirnova, O. L.; Gura, S.; Skorynina-Pohrebna, O.; Khoroshev, O.; Shkolnikova, T. V.
The investigation data of the formation peculiarities of oxide films on the Ti6A14V alloy in tartaric acid solutions have been given. It is shown that the behavior of alloy forming dependences is conditioned by the anode current density. At jₐ < 0.5 A∙dm⁻² the continuous oxide film is not formed on the alloy surface and the preset value of the final voltage on the cell is not reached. With an increase in jₐ > 0.5 A∙dm⁻², alloy forming dependences show a linear behavior that is indicative of the formation of low porous films. In these conditions, the oxide film formation rate is in direct proportion to the value of jₐ. The electrochemical oxidation of Ti6A14V alloy in tartaric acid solutions results in the formation of interference-colored oxide films. The oxide film ultimate thickness and color are defined by the preset voltage and are independent of the current density and electrolyte concentration. The isolating properties of obtained films were studied by way of the cathode polarization of oxidized specimens in the sulfate copper-plating electrolyte. The research done allows us to make a conclusion that electrochemical copper deposition is a convenient tool for the detection of defective spots in oxide films. It is shown that due to the specific features of the reduction kinetics of Cu²⁺ ions on the oxidized titanium it is reasonable to use for the studies the initial sections of polarization dependences that correspond to ΔE = 0.2-0.25 V. The alloy polarization dependences allow us to establish unavailability of apparent dependences between the oxidation current density, the electrolyte concentration, the cell final voltage value and the polarization that occurs during the Cu²⁺ ion reduction. The anodic connection of copper-coated specimens conditions the reversible dissolution of a greater portion of the specks of copper deposits. It is indicative of the electron conduction of film defects. The obtained data allow us to vary the electrolysis parameters in a wide range with no significant influence of the treatment mode of Ti6A14V alloy on the quality of oxide coatings.
Carbon Steel (St.3) Corrosion Caused by the Circulating Water Flow
(Kyiv National University of Technologies and Design, 2018) Pilipenko, A. I.; Pancheva, H.; Khrystych, E. V.; Smirnova, O. L.
Studying the kinetics of electrode reactions on copper, silver and gold in acid thiourea-citrate electrolytes
(2019) Smirnova, O. L.; Brovin, A. Yu.; Pilipenko, A. I.; Zhelavska, Yu. A.
The kinetics of electrode reactions that take place on copper, silver and gold electrode in acid thiourea-citrate electrolytes has been studied. It is established that the anodic dissolution of metals is accompanied by the formation of stable thiourea metal complexes of a cation-type complex. The citric acid provides the acidic pH-value of the solutions and contributes to the active dissolution of anodes. The ionization rate is limited by the diffusion of charged particles into the electrolyte volume. The cathode reduction of metals obeys the mechanisms of mixed kinetics that includes the diffusion and the preceding chemical complexes dissociation reaction. The charge of the complex ions of copper, silver and gold is +1. Therefore, their dissolution at the anode and reduction at the cathode occurs with the maximum possible electrochemical equivalent.

Кафедра "Технічна електрохімія"

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