The effect of plasma treatment on the surface chemistry and structure of ZnMgAl coatings

Abstract A principal investigation on the effect of atmospheric pressure plasma on Zn1.5Mg2.5Al coating was performed by means of X-ray photoelectron- and Auger electron spectroscopy as well as by transmission electron microscopy. The type of the medium used to generate the plasma influenced significantly the impact of the proceeded treatment. Although a mild surface cleaning and oxidation effect was observed for air, N2 or H2O plasma, mixed air + H2O and N2 + H2O plasma types already caused a remarkable altering of the chemical composition, structure and thickness of the coating surface layer, a similar effect to an initial corrosion attack.