Cold sealing mechanism of anodic oxide films on aluminum. II: Cold Sealing models of oxide films

Weight gain during cold sealing and the dissolution characteristics of anodic oxide films formed in sulfuric acid solution on aluminum were investigated by means of the gravimetric method, Auger electron spectroscopy and transmission electron microscopy. Two kinds of cold sealing models were proposed. For thin oxide film, the products of the sealing reaction that takes place throughout the film, gradually fills the pores completely. For thick oxide film, the sealing reaction mainly occurs at the outer layers, but the inner layers remain unfilled