Plasma electrolytic oxidation (PEO) treatment of zinc and its alloys: A review

Recently, few papers about plasma electrolytic oxidation (PEO) treatment on pure zinc, ZA27 and Zn-0.1 wt.% Mg alloys have been reported. The PEO procedure of pure zinc in electrolytes of KOH showed that the KOH amount and additives control the growth of a compact and dense oxide. The additives are mostly included in an outer film of the coating, while the inner layer of coating is mainly formed by ZnO. For ZA27 alloy, the PEO technique made...