Electrochemical deposition and characterization of zinc-nickel alloys deposited by direct and reverse current

Zinc coating is widely used as a protective coating on steel and one of the most important problems in galvanizing is the improvement of the protective and functional properties of Zn coatings. ZnNi alloys electrochemically deposited on steel under various deposition conditions were investigated. The alloys were deposited on a rotating disc electrode and on a steel panel from chloride solutions by direct and reverse current. The influence of reverse plating variables (cathodic and anodic current densities and their time duration) on the composition, phase structure and corrosion properties were investigated. The chemical content and phase composition affect the anticorrosive properties of ZnNi alloys during exposure to a corrosive agent (3 % NaCl solution). It was shown that the ZnNi alloy electrodeposited by reverse current with a full period T= 1 s and r = 0.2 exhibits the best corrosion properties of all the investigated alloys deposited by reverse current.