Electrochemical deposition and corrosion stability of Zn-Co alloys

Abstract

Electrochemically deposited Zn-Co alloys under various deposition conditions were investigated using anodic linear sweep voltammetry for phase structure determination, scanning electron microscopy for surface morphology analysis, atomic absorption spectroscopy for determination of chemical composition, and polarization measurements and open circuit potential measurements for determination of corrosion properties. The influence of deposition current density, temperature, and composition of deposition solution on the phase structure and corrosion properties of Zn-Co alloys was studied. It was shown that the ratio of cobalt to zinc ions in the plating bath strongly affects the chemical content and phase structure, as well as corrosion stability, of Zn-Co alloys. Zn-Co alloys deposited from plating baths with the lowest and the highest ratios of cobalt and zinc ions exhibited the lowest corrosion rate.