High Entropy Rare-earth Oxide (HERO) Coatings for Refractory Alloys
Project Innovation + Advantages:
A turbine engine's combustion environment can rapidly degrade high temperature alloys, which means they must be coated. This coating must be able to expand with the alloy so it adheres during temperature cycling, prevent combustion gases from permeating to the underlying alloy, and possess ultra-low thermal conductivity to protect the alloy from high surface temperatures. The University of Virginia will develop a novel coating for high temperature alloys that enables both a dramatic increase in upper use temperature for turbine engine blades and increased engine efficiency. The proposed coating will achieve these goals via a mixture of oxides of rare earth metals with different mass, ionic size, and charge. This mixture enables adjusting the coating’s thermal expansion to match the underlying alloy and reduce its thermal conductivity. It will be manufactured using conventional air plasma spray or novel slurry-based processing to reduce cost and enable reparability.
Combining development of new ultrahigh temperature materials with compatible coatings and manufacturing technologies has the potential to increase gas turbine efficiency up to 7%, which will significantly reduce wasted energy and carbon emissions.