Effect of Vanadium-doping on the Electrical and Thermal Conductivity of Microarc Oxidation Coatings on Aluminum Alloys

Abstract

Vanadium was doped in microarc oxidation (MAO) coatings by incorporating ammonium metavanadate (NH4VO3) into base electrolyte. The electrical resistivity of the vanadium-doped coating and the undoped coating was measured at different voltages, while the thermal diffusivity of both coatings was tested at different temperatures. The results indicate that the content of vanadium in coating is about 8.5 at.%. The doped vanadium shows remarkable influence on the microstructure of coating. The electrical resistivity of MAO coating is independent on vanadiumdoping but significantly dependent on the testing voltage. Furthermore, the vanadium-doping can enhance the thermal diffusivity of MAO coating.