Corrosion properties of the Ni/Cu nanocrystalline multilayers coatings

This paper presents results of investigations reported to nanocrystalline coatings of Ni, Cu, N/Cu produced by electrodeposition on the carbon steel S235JR substrate. The coatings were characterized by such research techniques as X-ray diffraction (XRD), scanning electron microscopy, optical microscopy, Vickers microhardness measurements and electrochemical corrosion tests. Images of cross sections and surfaces of produced coatings and their corrosion damages are presented. The results of corrosion tests realized for investigated coatings are presented in the forms of potentiodynamic polarization curves, j = f (E) and corrosion potentials and currents. The Ni, Cu, and Ni/Cu coatings produced by the electrodeposition processes exhibited nanocrystalline structures and compactness as well as uniform thickness over the entire coated surface, and their adhesion to the substrate were very good. They can be considered as good corrosion protections for steel substrate in damage environments.