Electrodeposition and properties of Zn, Zn-Ni, Zn-Fe and Zn-Fe-Ni alloys from acidic chloride-sulphate electrolytes

Zn, Zn-Ni, Zn-Fe and Zn-Fe-Ni films have been deposited by electrochemical deposition technique onto steel plate substrates. The objective of this study was to characterise the corrosion properties of these alloys in saline solution for the application as new environmentally friendly sacrificial coatings in the protection of steel structures. The morphological and structural properties of the alloys were systematically studied using XRD and SEM techniques. Cyclic voltammetry of the individual metals was performed to help understand the electroplating process of the films. Grain sizes of the films were calculated using Scherrer's formula. Partial substitution of Zn to Fe and Ni leads to an improvement in the corrosion resistance. Compared with other zinc alloys, the Zn-Ni alloy deposit was the noblest.