STTR Phase I: Demonstration of Enhanced Corrosion Resistance using a Nano-composite Thermal Barrier Coating

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This Small Business Technology Transfer (STTR) Phase I project will experimentally validate the theory that inclusion of nanostructures within the Thermal Barrier Coatings (TBC) will enhance the resistance to hot corrosion by increasing the fracture strength of the ceramic thereby inhibiting grain growth similar to reinforcing concrete with rebar. The grain growth leads to the formation and growth of interconnected cracks needed for wicking of molten salts that result in spallation. The novel nanocomposite coating would find application within fossil energy power generation devices (dirty fuel) and aircraft engines (marine environments). Current technology turbine blades are comprised of single crystal nickel superalloys. Historically, protective TBC have allowed for operation of the turbine while subjected to hot gases exiting the combustor at temperatures exceeding the superalloy melting point. The increase in turbine inlet temperature has yielded improvements in efficiency, power density, and emission quality. However, these protective barriers are susceptible to hot corrosion, an electrochemical reaction between the superalloy and molten salts resulting in spallation or fragmentation of the thermal barrier coating. The reduction of premature spalling will allow for the simultaneous increase of the turbine inlet temperature and the reduction of the turbine coolant air. This combination has the potential to increase efficiency, reduce toxic emissions, and save capital costs.