| Abstrakt: |
In a paper published in the November 2009 of this journal, the author challenged the validity of the "barrier layer" theory of coating formation in the anodizing of aluminum. It was shown that there is adequate evidence that the barrier layer was not a layer at all, but was instead a transition zone between the metal and the anode oxide film. Additionally, the theory failed to account for the effect of material composition and structure on die formation, structure and growth processes. The author concluded that the theory is no longer valid. In this paper, a new model for the formation of anodic coatings is presented. This model is based on the initial formation, morphology and growth processes being highly dependent on the lattice vacancy and defect structures. These factors ore further modified by the presence of alloying and impunity metals. [ABSTRACT FROM AUTHOR] |
