Kinetic model of composite coatings electrodeposition assuming irreversible adsorption of dispersed particles on a growing metal substrate

A kinetic model of electrochemical deposition of composite coatings has been developed, which assumes irre-versible adsorption of dispersed particles on a growing metal matrix. The irreversibility of particle adsorption is due to energy consumption required for the complete or partial removal of adsorption layers and solvate shells present on the surfaces of dispersed particles and a metal matrix, which is a necessary condition for the forma-tion of a strong adhesive bond. The corresponding kinetic equations are derived that reflect the dependence of the content of a dispersed phase in the composite on the concentration of particles in the electrolyte, their aver-age size and current density of metal deposition. The resulting equations are used to calculate adsorption rate constants on the basis of experimental data on the electrodeposition of nickel-titania composite coatings from an aqueous electrolyte and an electrolyte based on a choline chloride-containing deep eutectic solvent. The influence of current density on the adsorption rate constants in these electrolytes is revealed and interpreted.