Nondestructive Inspection of Phosphoric Acid Anodized Aluminum Panels for Contamination.
Abstract
This report describes a study of nondestructive inspection (NDI) for contaminants on phosphoric acid anodized aluminum alloys (A1 7075-T6 and A1 2024-T3). Contamination is used in the broad sense to include surface preparation process errors (such as incorrect anodize time or voltage) and handling damage as well as organic contamination from humans and smog. Panels were deliberately contaminated to various levels and then inspected by automated scanning with three surface tools. The tools were, ellipsometry, surface potential difference (SPD), and water contact angle. Ellipsometry proved to be the most useful, detecting all types of contamination. SPD was partially successful for processing errors and organic contamination but was not successful for handling damage. Contact angle measurements were successful for nonpolar organic contamination only. The anodic films are too thick for useful photoelectron emission (PEE) but this technique is very useful for other surface treatment such as FPL etch. The best NDI instrument should include ellipsometry and SPD but ellipsometry alone will probably be adequate. SPD alone would not be adequate. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1977
- Accession Number
- ADA044241
Entities
People
- Tennyson Smith