In this paper, zirconium oxide ceramics coating (ZrO2) were produced on Zircaloy-4 alloy using plasma electrolytic oxidation (PEO). Sodium silicate and Sodium aluminate based electrolyte was selected in PEO process and the effects of the concentration of Sodium aluminate (0, 2.5, 5, 7.5, and 10 g/L) on the microstructure, phase structure and the behavior of corrosion of formed coatings. In orde...