Microstructural and corrosion behavior of MAO coated 5052 aluminum alloy

In this paper, the morphology, phase composition and corrosion behavior of micro-arc oxidized 5052 aluminum alloy were analyzed. A uniform micro arc oxidation (MAO) coating was performed on 5052 aluminium alloy in different electrolytes (with and without borax additives) for 30 min. The MAO coating thickness was measured around 17-24 mu m and nanocrystalline gamma-Al2O3 were identified in the MAO coating using XRD analysis. The coating thickness was measured using the eddy current technique and morphology of the coating was analyzed using SEM. The coating formed in the electrolyte with borax showed reduced porosity compared to the sample coated without borax. The corrosion behavior is analyzed by Potentiodynamic polarization. The MAO coated sample offers higher corrosion resistance when compared to the uncoated specimen due to higher corrosion potential. (C) 2019 Elsevier Ltd. All rights reserved.