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At the present time, the electrodeposition of chromium metal coatings of sufficient thickness and quality is possible only from chromium plating electrolytes containing chromic acid. The authors investigated the effect of the composition of chromium plating electrolyte on the quality of the resulting metal coating. It has been demonstrated that the introduction of organic additives, of gallic acid in particular, leads to significant changes in the surface of the metal deposit and to a decrease in its hardness. Assumptions have been made about the influence of organic additives on the metal deposition process. The experimental data on the content of gases in the chromium deposits obtained from electrolytes with gallic acid additive and without it have been presented.

The authors have studied the influence of the electric current density, temperature, electrolyte composition on the properties of electroplating Chromium-Zinc deposits. The dependence of the maximum yield of metal on the physico-chemical characteristics of the solutions for electroplating of Chromium and Cr-Zn alloy has been shown. Chromium-Zinc coatings have been obtained from electrolytes based on chromic acid in the presence of organic additive (4-methylaminophenol). Abrupt nonlinear changes in density, viscosity, surface tension, specific electrical conductivity due to structural transformations in electrolytes are observed at the concentration of zinc sulphate of 4070 gramm / litr (further in the text - g/l), and the organic additive of 2-5 g/l. The obtained model has been applied to predict the optimal electrolyte compositions for the processes of Cr-Zn alloy formation, which will allow reducing the research efforts concerning the electrochemical studies of the given process when chromic acid solutions are used. The coatings exhibit high hardness, corrosion resistance, wear resistance, low internal stresses.

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The process of electrodeposition of a tin-lead alloy from hydrofluoride electrolytes by pulsating currents has been investigated. The influence of the electric mode on the alloy composition and properties of the resulting precipitates was studied: current efficiency, microhardness, specific electrolytic resistance, and internal stresses of the precipitates.