The US Navy has reduced to practice and patented easy-to-apply, trivalent chromium-based conversion coating for aluminum alloys, anodized aluminum, and sacrificial coatings. This trivalent chromium pretreatment and post treatment (TCP) technology offers a more environmentally benign coating than highly toxic hexavalent chromium, without sacrificing corrosion resistance. TCP also provides superior corrosion resistance as compared to non-chromate alternatives. The patents cover a variety of formulations that allow for optimization for specific applications.
Background: It is necessary to improve the corrosion resistance and bonding of paints to aluminum alloys, anodized aluminum, and sacrificial coatings by treating the surface with a supplemental coating. Historically, this practice has favored the use of hexavalent chromium solutions. Chromate films provide outstanding paint adhesion and corrosion resistance and are easy to apply by various methods including immersion, spraying or wiping. However, hexavalent chromium is highly toxic and is a known carcinogen, creating operator and disposal problems. The Navy’s patented Trivalent Chromate Pretreatment/Post treatment is more environmentally benign and is non-carcinogenic. This provides both environmental and performance benefits.
- TCP does not contain hexavalent chromium
- Improved corrosion protection and paint adhesion compared to non-chromate alternatives
- Single step application process
- Cost competitive with hexavalent chromium
- US Patents: 6,375,726; 6,511,532; 6,521,029; 6,527,841 are available for license and commercialization
- TCP is a fully developed, fully competitive alternative to hexavalent chromium and has better performance characteristics than non-chromate alternatives
- Samples of TCP for testing and performance verification can be made available
- The Navy inventor will be available for limited consultation and discussion