Influence of Na₂WO₄ additive in electrolyte on properties of plasma electrolytic oxidation coatings on H62 brass

Abstract

In order to improve the corrosion resistance of brass treated by plasma electrolytic oxidation (PEO), Na2WO4 additive was introduced into a mixed electrolyte of sodium silicate and sodium hydroxide, and a composite oxide coating was formed on the surface of H62 brass. The effect of Na2WO4 concentration from 0 to 3 g/L in silicate-based electrolyte on the properties of PEO coatings was investigated by SEM, EDS, XRD and electrochemical workstation. The results show that the element of W in the form of metal oxides can be successfully incorporated into PEO coatings. The addition of Na2WO4 can significantly improve the corrosion resistance of PEO coatings, and the best corrosion resistance is obtained when the addition amount is 1.0 g/L.