Porous Anodic Films Formed on Aluminium in Chromic Acid

Publisher Website
Google Scholar
Abstract
Anodic films have been formed at constant voltage in chromic acid under conditions which allow the formation of relatively thick porous films. STEM/EDAX analysis of the cell walls of films, formed initially into the steady state current density region and then ion beam thinned, suggests that no chromium is incorporated into the cell material. CTEM/EDAX analysis of thin films formed for relatively short anodizing times again suggests that no chromium is incorporated into the film material. Thus, films formed in chromic acid appear to be composed of relatively pure alumina, unlike the films formed in the other major anodizing acids, where a significant contribution to the growth of the film arises from acid anion-incorporated film material.