Characterization of Chromic-Acid Anodized 2024-T3 Aluminum Adherends
Abstract
The topography of 2024-T3 aluminum-alloy surfaces has been characterized by using high-magnification transmission electron microscopy (TEM) at various stages during the chromic-acid anodizing procedure used to prepare aluminum surfaces for adhesive bonding. The surface structure characteristic of the unsealed chromic-acid anodized alloy was found to form during the first 6 minutes of the 37-1/2-minute anodizing cycle; the surface characteristic of the sealed anodized alloy was found to form during the last half of the 8-minute sealing cycle. The surface structure of FPL deoxidized and of unsealed anodized surfaces consists of a repeating pattern of close-packed depressions 200 to 800 angstrom units in diameter. The structure of the sealed surface consists of crevices 500 to 2,000 angstrom units wide between mounds of material formed during sealing. The chemical composition of the surfaces was determined after anodizing and also after sealing the surface, using electron spectroscopy for chemical analysis and auger electron spectroscopy. These surfaces were found to consist of aluminum, oxygen, carbon, and nitrogen with traces of silicon and maganese. Copper and magnesium, two of the major alloying elements in the alloy used, were not detected.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1977
- Accession Number
- ADA048756
Entities
People
- Carolyn A. Westerdahl
- William J. Russell
Organizations
- United States Army Armament Research, Development and Engineering Center