NDE Method for Characterizing Anodized Al Surfaces
Final rept. 1 Sept 77-31 Jul 78
ROCKWELL INTERNATIONAL CORP THOUSAND OAKS CA SCIENCE CENTER
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This report describes a study of the relationship between nondestructive inspection NDI for contaminants on phosphoric acid anodized PAA Al 7075-T6 and bond strength and degradation that results from the contamination. Contamination is used in the broad sense to include surface preparation process errors e.g., incorrect anodize time or voltage and handling damage, as well as organic contamination from humans and smog. It is demonstrated that the ellisometric technique can adequately reveal contamination at levels below and in the range that significantly degrades bond integrity. The ellisometric technique is not restricted to flat panels, as demonstrated by mapping a panel with 7 cm radius of curvature. However, mapping of curved surfaces would be facilitated by passing the sensor head over the panel rather than the panel under the head. This and mapping on NDI of smaller numbers of various shaped parts requires the development of a small miniaturized hand-held contamination tester. The design of such a tester is presented.
- Adhesives, Seals and Binders
- Test Facilities, Equipment and Methods