Novel erosion and temperature resistant overlay coating systems for turbomachinery

 
Compressor blades and turbomachinery components offer significant challenges for coatings formulators. An ideal coating system should provide resistance to elevated temperatures up to 250°C, corrosive environments, excellent intercoat adhesion to both basecoat and substrate, aerodynamic smoothness, and resistance to erosion from particles and droplets in the gas flow. These properties have been carefully balanced in a new topcoat based on reactive polyurethane chemistries, and designed to work in complement with corrosion resistant metal ceramic basecoats. Since the properties depend upon the temperature at which the resins are cured, property optimization was performed on panels cured at maximum service temperature. Further investigations optimized stoichiometric ratios, pigment selection, PVC, and cure temperature to yield attractive high performance coatings. Erosion resistant topcoats are being developed for use in both Chromium (VI) containing and Chromium (VI) free corrosion resistant basecoats on steel substrates.