Selected mechanically polished and dried samples of AA5083-O alloys were electropolished in 25% perchloric acid solution in ethanol at temperatures below 10 °C. After electropolishing, the samples were rinsed in ethanol followed by a rinse in deionised water. The electropolished samples were then anodized in Barker's reagent (2.5% fluoroboric acid solution) using 20 V at room temperature for 120 s. All anodized samples were immediately rinsed in deionised water before drying in a cool air stream.
The Barker's reagent-formed anodic oxide layer was dissolved in a solution containing 20 g Cr2O3 + 30 ml HPO3 in 1 l of deionised water for examination of the resulting surface features after anodizing. The dissolution was carried out at a solution temperature of 60 °C for 6 min.