Surface microstructure and corrosion resistance of electrodeposited ternary Zn-Ni-Co alloy

The electroplating of ternary Zn-Ni-Co alloy, the influence of cobalt codeposition on crystal orientation, surface topography and corrosion resistance were investigated and contrasted with the characteristics of Zn-Ni electrodeposits. It was found that the Zn-Ni-Co alloy showed better corrosion resistance, in 3% sodium chloride, in comparison with Zn-Ni alloy electroplated under similar conditions. The best corrosion resistance was observed for ternary deposits having 11.24% Ni and 6.52% Co. The crystal orientation and surface topography were characterized by means of x-ray diffraction analysis and scanning electron microscopy, respectively. Substrate: mild steel.