Therefore, oxide coatings were produced on the co-extruded Al/Mg
compounds by simultaneous plasma electrolytic oxidation (PEO). A silicate-alkaline and a silicate-phosphate-alkaline electrolyte
were used for the coincident production of coatings with a thickness of several 10 microns on both the aluminum and the
magnesium component. The inherent flaws of the coating (pores, cavities) allow for the infiltration with an epoxy-based sealant.
The electrochemical behavior of the magnesium component covered with the oxide coatings with and without sealing was
compared with reference to the unmodified surface. The surface modification (PEO w/wo sealing) significantly decreases the
corrosion susceptibility of the Mg component, and thus of the compound