Kinetics of Electrodeposition of Nickel–Cobalt–Alumina Composite Electrochemical Coating

The kinetic features of electrodeposition of wear- and corrosion-resistant composite electrochemical coating (CEC) of nickel–cobalt–alumina from a chloride colloidal electrolyte are studied. The application of potentiodynamic, chronopotentiometric and temperature–kinetic methods, as well as the use of the calculated temperature coefficient of reaction rate and the diffusion coefficients of nickel ions, enabled us to determine the mechanism of CEC electrodeposition. The analysis of the data on the kinetic features of CEC electrodeposition showed that the nature of the slow stage of the process is associated with the electrophoretic transfer of electroactive particles to the cathode and the stage of the overgrowth of dispersed particles adsorbed on the cathode surface with the electrodeposited metals, which proceed at comparable rates.