Plasma electrolytic oxidation has been used to create a sublayer on aluminum alloy to form a composite coating to improve the corrosion properties of the processed material. The evolution of protective characteristics of the resulting coatings were examined by potentiodynamic polarization during the exposure in a salt spray chamber. The absence of pittings after a 10-day test for the entire series of composite coatings on aluminum alloy confirms the high level of barrier properties of the coated samples.