Influence of Fluorozirconic Acid on Sulfuric Acid Anodizing of Aluminum

Abstract

© The Author(s) 2017. Published by ECS. All rights reserved. The effects of additions of fluorozirconic acid to sulfuric acid on the anodizing behavior of aluminum have been investigated under a constant voltage at temperatures of 0 and 20◦C. The fluoroacid increased the rate of film growth, with a dependence on the fluoroacid concentration, the electrolyte temperature and the anodizing time. Compositional analyses showed that fluorine species were present in the films. However, zirconium species were absent. The fluoroacid generally enhanced film dissolution, although this effect was less important at low fluoroacid concentration, low electrolyte temperature and short anodizing times. Sodium fluoride additions influenced the anodizing behavior similarly to the fluoroacid.