Formation and Breakdown Behavior of Anodic Oxide Films on Aluminum in Dilute NaOH Solutions

摘要

The mechanism of formation and the breakdown of anodic film in dilute NaOH solutions were examined, amount of dissolved aluminum ions was by using ICP-AES, image of anodic oxide films by using FE-SEM and TEM. Anodic oxide films were formed on aluminum in 5 X 10~(-5) approx 5 X 10~(-3) M NaOH solutions at different current densities. During anodizing, anodic oxide films grew thicker, and the film growth was accompanied by the formation and repairing of many voids and imperfection in the oxide film. At the final stage, the growth of anodic oxide films was ceased by film breakdown, and the film breakdown potential became higher at lower solution concentration and lower current densities. The breakdown potential at 5 X 10~(-5) M NaOH solution was 1550V.