Characterization, Modeling, and Accelerating Emulation of Aircraft Coating Exposure and Degradation
NORTH DAKOTA STATE UNIV FARGO
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The Air Force stations its aircraft in many geographical locations worldwide, and some of these sites have specific exposure conditions and atmospheric chemistry that make them especially potent in their effects on aircraft coatings. In a period in which the Air Force is making the transition away from chromate-based corrosion protection for its air fleet, it is very important that the test methods used in qualifying new protective coatings and metal pretreatments properly reflect the stresses and conditions to which the aircraft are exposed. Further, these tests must be truly accelerated tests in that they MUST accurately reflect the stresses and hazards that the aircraft and its coatings systems will see during its lifetime. The present suite of tests now used in coating accelerated testing need to be upgraded to reflect the current state-of-the-art in environmental science concerning the exposure which the aircraft will really see, as well as the state-of-the-art in measurements and modeling of coating degradation and failure in the field and the laboratory. NDSU proposes to do an extensive review and update of the suite of tests now currently used to qualify coatings and coating systems for DoD aircraft. It will choose those tests, such as ASTM B117, that have obvious flaws, and develop or implement alternate test protocols that reflect the best current science and document these measurement as appropriate test methods, including the accelerating factors of the test, and the modeling of the test to make it predictive of future performance of the coatings. The coatings used in developing the improved methodologies will include both the existing chromate-based systems upon which all of the present tests and qualification procedures have been built and biased as well, as well as all the best of the chromate replacement coatings such as the Mg-rich technology from NDSU.
- Coatings, Colorants and Finishes