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A MA8 magnesium alloy substrate was pre-impregnated in aqueous solutions of cerium(III) nitrate and glycerol before microarc oxidation, which was used to form oxide ceramic coatings from a silicate–alkaline electrolyte containing fluoride ions. The corrosion-protection properties of these coatings on the pre-impregnated alloy surface were assessed using potentiodynamic polarization curves. Electrochemical parameters calculated from the potentiodynamic polarization curves showed that the presence of the oxide ceramic coating on the surface of MA8 magnesium alloy significantly reduces the corrosion current density and increases the polarization resistance. It was determined that the pre-impregnation of the MA8 magnesium alloy substrate in aqueous solutions of cerium(III) nitrate and glycerol affects the mechanism of the corrosion damage. [ABSTRACT FROM AUTHOR]

The formation of oxide coatings on D16 aluminum alloy by microarc oxidation (MAO) treatment in the anodal-cathodal mode with discharge interruption in the basic silicate-alkali electrolyte (composed of three solutions) and in the mode without charge interruption in a silicate-alkali electrolyte of similar composition is studied. We find that the mechanism of formation of oxide ceramic coatings depends on the mode of MAO treatment. Addition of sodium tetraborate to the electrolyte has an impact on the properties of oxide ceramic coatings fabricated using the mentioned treatment modes. We demonstrate that MAO treatment in the anodal-cathodal mode with discharge interruption gives rise to a higher content of high-temperature aluminum oxide phase (α-Al2O3) in coatings and enables the formation of thin (up to 25 μm) oxide ceramic coatings that retain all unique properties of this type of coatings. [ABSTRACT FROM AUTHOR]

Formation of vanadium-containing oxide ceramic coatings in the stagewise microarc oxidation process on the surface of the D16 aluminum alloy is studied. Conclusions as to the mechanism of their growth are made on the basis of analysis of the change in the element composition and surface morphology of the coatings. The prospects of using such coatings as catalytically active systems are shown. [ABSTRACT FROM AUTHOR]

Fundamental aspects and specific features were studied of how composite coatings with oxygen-containing compounds of manganese are formed on the surface of D16 alloy in the course of the microarc oxidation from a silicate-alkaline electrolyte in the anodic-cathodic mode with interrupted discharge. The influence exerted by the concentration of potassium permanganate in the electrolyte on the elemental composition, morphology, and structure of the coatings was examined. It was found that the coatings are promising as catalytically active and corrosion-protection systems. [ABSTRACT FROM AUTHOR]