Exploration of Corrosion Resistance of Alizarin CoatedAnodized Aluminum Using Electrochemically Methods

The effect of coloring condition of aluminum with Alizarin (1, 2-dihydroxyanthraquinone) on the corrosion of Al in sulfuric acid solution was studied using cyclicvoltammetry and impedance measurement methods. The changes in the corrosion resistance of colored aluminum plates were evaluated by measuring the magnitude of Impedance and cyclic Voltammetric responses of anodized and colored plates.The current and threshold potential of corrosion responses strongly depends on the applied conditions during anodizing, coloring and sealing stages. In this study, the surfaces of the aluminum plates were also studied by Scanning Electron Microscopy(SEM). Comparison of SEM images of the colored and uncolored aluminum specimens showed that the uncolored surface contained a significant numbers of pits. The results indicated that coloring aluminum with Alizarin at the optimum conditions and sealing it with boiled water could reduce corrosion on this metal.