Sample preparation and characterization of artificially aged aircraft coatings for microstructural analysis

The military specification coating system under study (MIL-PRF-85285C and MIL-PRF-23377G) degrades severely after accelerated weathering. Typical degradation includes deterioration of the polyurethane-based resin system in the topcoat and is observed as a visible change in the color. Increased porosity and some physical deterioration were also observed. In addition, some inorganic pigments in the primer appear to migrate into the topcoat during simulated exposure.