Understanding Corrosion Protection Requirements for Adhesive Bond Primers
Abstract
Based on tests conducted in this project, hexavalent chromium corrosion inhibitors in adhesive bond primers were found to have less significance than expected for adhesive bondline environmental durability. Cytec BR 6747-1 (chromated) and BR 6747-1NC (noninhibited) were the basis primers for testing and analysis. Additional tests using 3M EW-5000 (chromated), 3M EW-5000ET (non-chromate inhibitor), and EW-5000-NC (experimental, noninhibited) primers served to validate results. Test configurations included aluminum wedge crack extension and double cantilever beam specimens bonded with epoxy film adhesives, which were exposed to long-term marine atmospheric and accelerated indoor corrosion environments. Samples also underwent mechanical and electrochemical stress cycles and were subsequently post-analyzed for failure mode, moisture ingress, and corrosion. Many of the traditional and novel tests conducted during the effort did not show significant differences between chromated and nonchromated bond primers in adhesive bondlines. Though certain rigorous tests used to qualify materials and processes for bonded joints did show chromated primers provide a positive contribution to environmental durability, even these tests revealed surface preparation is the dominant factor for aluminum bonded joint environmental durability performance.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 15, 2017
- Accession Number
- AD1092341
Entities
People
- Diane Kleinschmidt
- Eileen Kutscha
- James Mazza
- John Stropki
- Kay Blohowiak
- Kevin Tienda
- Mark Jaworowski
- Robert E. Jensen
- Vinay Gadkari
- Weilong Zhang
Organizations
- Naval Air Warfare Center Aircraft Division