Corrosion Finishing/Coating Systems for DoD Metallic Substrates Based on Non-Chromate Inhibitors and UV Curable, Zero VOC Materials
Abstract
Corrosion resistant coatings containing non-chromate inhibitors and no volatile organic compounds were developed and evaluated for DoD applications. The technical effort involved cerium based conversion coatings (CeCCs) and ultraviolet (UV) light curable coatings containing corrosion inhibitors. This approach would replace the current three layer, environmentally unfriendly coating system with a benign, two layer multifunctional UV (MUV) coating system. Replacement of corrosion coatings on high strength aluminum alloys used for military aerospace applications was the main focus for the technology developed. Work on the impact of processing parameters on CeCC corrosion performance, including the use of gelatin in the deposition solution and post deposition treatment in phosphate solution, resulted in significant improvement in CeCC protection of high strength aluminum from corrosion. The identification of sub-surface crevices in the Al substrates that form during CeCC deposition helped explain results previously not understood. Application of MUV coatings with Hybricor 204 corrosion inhibitor repeatedly demonstrated the ability to protect scribed, chromate conversion coated Al substrates during ASTM B117 salt spray testing. Drawbar applied MUV coatings on CeCC passed salt spray testing while spray applied MUV on CeCC formed blisters during ASTM B117 testing. MUV coating properties such as flexibility and fluid resistance were improved throughout the project and demonstrated the potential to meet aerospace requirements. Results indicate that the technology holds promise for replacing existing environmentally hazardous corrosion coatings for military applications.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2010
- Accession Number
- ADA534279
Entities
People
- Matt O'keefe
Organizations
- Missouri University of Science and Technology