In this study, plasma electrolytic oxidation (PEO) composite coating on AZ31B magnesium alloy was performed in the suspension of glass particles (particle size of 500 nm). The effect of glass particle concentration on corrosion and wear behavior of coatings were investigated by potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and pin on disk tests. The results showed that the addition of glass particles with 5 g/l concentration enhanced corrosion and wear resistance of the coating due to the filling or sealing coating pores with molten glass. A uniform surface of the composite coating is obtained (0.1 µm roughness average) at a concentration of 5 g/l. Along with the further increase in concentration, the preferred locations in the coating process are decreased leading to the non-uniform coating. This consequently increases the un-melted particles on the surface. Corrosion current density at the concentration of 5 g/l glass particles decreased up to five times rather than coating without glass particles (from 13.71 to 2.64 µA.cm2). Also wear rate at an optimum concentration of glass particles decreased from 0.48 to 0.05 µg/N.m.

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