AFRL Develops High-Temperature Aircraft Camouflage Coating Published June 4, 2007 By Materials & Manufacturing Directorate AFRL/ML WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- Working under a Small Business Innovation Research (SBIR) contract, scientists from AFRL and the Texas Research Institute developed a high-temperature aircraft camouflage coating for use on the titanium slats of C-17 aircraft. This coating will significantly increase the survivability of operational aircraft against the threat of man-portable weapons and provide enhanced thermal performance for future aircraft. The camouflage coating prolongs aircraft survivability by reducing the gloss and reflectance of uncoated high-temperature components. Current military aircraft require a low-gloss coating for survivability. These coatings are typically polymeric-based products, and they experience severe deterioration with long-term exposure to temperatures above 250°F. Therefore, the areas of the aircraft subject to high temperatures are often left uncoated, leaving the aircraft vulnerable to attack. The C-17's titanium slats are located on the leading edges of the aircraft's wings. During extended ground maneuvers, the slats are subjected to temperatures exceeding 800°F, primarily the result of engine thrust reversal. The heat causes discoloration and flaking of the existing polyurethane-based coating, exposing a highly visible metal surface. During Phase I of the SBIR effort, scientists developed a low-gloss coating capable of withstanding temperatures of 1200°F; the coating is compatible with titanium or superalloy structures and matches the color standard in place for the C-17 aircraft. Producing and testing sample coatings in laboratory batches, the scientists labored through numerous formulations in order to optimize the coating's thermal stability, processing, and performance. The team's testing included pull-off adhesion, fluid soaks, taber abrasion, and impact. As part of the Phase II SBIR project, scientists refined the coating, evaluated various application methods, and conducted more extensive testing for environmental durability. These Phase II activities resulted in the successful development of a single-component, pigmented polysilazane with ultraviolet, color, and thermal stability. The coating is easily applied using conventional spray equipment and does not require a post-cure process to achieve exceptional thermal performance. Furthermore, the product meets or exceeds many of the existing specification requirements governing the current camouflage coating. AFRL personnel plan to apply the new coating to C-17 aircraft during scheduled program depot maintenance and also intend to flight-test the product on a C-130 aircraft.