Formation of compositionally modulated Zn–Ni alloy coatings on steel

The results of experiments involving the compositionally modulated multilayer Zn–Ni alloy coatings obtained by electrochemical method are presented. The determination of morphology, corrosion resistance and surface roughness of obtained coatings and their hardness by Vickers method were described. It was found that coatings consisting of the highest number of sublayers (50) were characterised as having the best anti-corrosion properties, which arise from the alternating (anodic/cathodic) mechanism of the corrosion process and from the influence of the formed corrosion products. The multilayer structure of the obtained coatings also influenced coating morphology and the hardness of the obtained system.