CORROSION STABILITY OF ELECTROCHEMICALLY DEPOSITED Zn-Mn ALLOY COATINGS

Abstract

Zinc alloy coatings electrochemically deposited on steel from electrolytes with different components differ in their composition, homogeneity, porosity, structure and other characteristics that affect their corrosion resistance. Manganese is characterized by a very negative electrochemical potential and very high strength, prompting many researchers to study Zn-Mn alloys for the anti-corrosion purposes in the industry, especially automoti-ve. In this work it was examined the influence of the type of the electrolyte deposition on the current efficiency during electrodeposition of Zn-Mn alloys. Zn-Mn alloys were deposi-ted on steel from chloride, sulphate and pyrophosphate plating baths at different current densities. We have examined the influence of deposition current density on the current effi-ciency during electrodeposition, appearance of alloy coatings, as well as their corrosion sta-bility. It was shown that Zn-Mn alloys with the best corrosion properties, among all exami-ned ones, were obtained from chloride plating bath at 2 A dm -2 .