Review of nondestructive methods for evaluating adhesive bonding on anodized coatings.

The aerospace industry uses aluminum alloys which have a good strength-to-weight ratio, but they have poor corrosion resistance. Additionally, in some cases the aluminum surface may need to be exposed to the adhesive and attached to other equipment. Therefore, it is necessary to have a coating with both adhesive bonding and corrosion resistance. Most effectively, anodized coatings are used to achieve these goals. Oxides made by anodizing are porous and can improve the adhesive bonding of surfaces due to their porous structure. Anodizing is done by using various electrolytes and processes that affect adhesive bonding and adhesion strength dramatically. In this paper, we describe methods to assess the adhesive bonding of anodized surfaces. The evaluation methods are divided into two categories. Chemical analysis is performed on anodized surfaces in the first category, and in the second category, mechanical interlocking is evaluated. [ABSTRACT FROM AUTHOR]