Protection of Aluminum against Corrosion by Incorporation of Organic Inhibitors into Paints and Primers
Abstract
Selected organic compounds have been evaluated on the basis of their ability to inhibit corrosion of aluminum and their bonding compatibility with a specified metal-adhesive system. Organic amino phosphonate and silane inhibitors were applied to sulfuric acid-anodized (SAA) 7075-T6 aluminum either by direct adsorption from aqueous solution or by spraying an inhibitor-containing primer formulation. All specimens, including the SAA control, exhibited superior corrosion resistance properties with respect to a standard Forest Products Laboratory (FPL) etch treatment. Wedge test adhesion analysis allowed evaluation of the compatibility of inhibitor-treated specimens with an epoxy adhesive (FM- 123-2) to simulate the final paint system. The results showed that low concentrations (2-100 ppm) of nitrilotris methylene phosphonic acid (NTMP) forced crack propagation to occur cohesively in the adhesive -- the optimum performance for a given adhesive-adherend system. Phenylphosphonic acid (PPA) and two silane inhibitors (an aminosilane, A-0800, and an epoxysilane, Z-6040) also strengthened the oxide-polymer interface.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1984
- Accession Number
- ADA171655
Entities
People
- D. K. Shaffer
- G. D. Davis
- L. J. Matienzo
Organizations
- Martin Marietta