Zn–ZrO2 nanocomposite coatings: Elecrodeposition and evaluation of corrosion resistance

The Zn and Zn–ZrO2 composite coatings were produced by electrodeposition technique using sulphate bath. ZrO2 particles were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The ZrO2 particle size distribution in the plating bath and Zeta potential and the ZrO2 were measured using dynamic light scattering technique (DLS). The corrosion resistance properties of Zn and Zn–ZrO2 composite coatings were compared by examining the experimental data acquired through polarization, open circuit potential (OCP) and Tafel measurements. The corrosion environment was 3.5 wt% NaCl solution. The variation of amount of ZrO2 in the solution on their % wt inclusion in the composite and on composite microhardness was investigated. XRD patterns were recorded for Zn and Zn–ZrO2 coatings to compare their grain size. The SEM images of coatings before and after corrosion under chemical and electrochemical conditions were presented. The results were analyzed to establish the superiority of Zn–ZrO2 composite over Zn coating.