University of Maryland (UMD)

Gas turbines produce approximately 35% of the total electricity generation in the U.S. Improving their efficiency is important for reducing energy usage and carbon emissions. Similarly, higher efficiency aviation and other industrial turbines would improve the economics and reduce greenhouse gas emissions in these sectors. Gas turbine efficiency largely depends on the gas temperature at the inlet; the higher the temperature, the higher the efficiency. Gas turbine operational temperature is currently limited by its component materials, particularly those in the path of the hot gas such as turbine blades, vanes, nozzles, and shrouds. Turbine blades experience the greatest operational burden because they must concurrently withstand the highest temperatures and stresses. Currently, turbine blades are made of single crystal nickel (Ni)- or cobalt (Co)-based superalloys. After many years of refinements, their development has plateaued. There is a need to discover, develop, and implement novel materials that work at temperatures significantly higher than that of the Ni or Co superalloys if further efficiency gains are to be realized.

The University of Maryland will leverage a newly invented, ultrafast high-temperature sintering (UHS) method to perform fast exploration of new environmental-thermal barrier coatings (ETBCs) for 1300°C-capable refractory alloys for harsh turbine environments. UHS enables ultrafast synthesis of high-melting oxide coatings, including multilayers, in less than a minute, enabling rapid evaluation of novel coating compositions. By using UHS with fast-fail tests and modeling and analytics tools, the team will be able to explore hundreds of compositions and coating architectures to design and optimize 1700°C-capable ETBCs with different layer sequences, thicknesses, porosity levels, and novel compositions. Hundreds of ETBCs will be fabricated on refractory alloy substrates and tested for thermal conductivity, thermal stability, resistance to thermal cycling, and other properties. The 1700°C-capable ETBCs on the 1300°C-capable alloys could improve the efficiency of natural gas turbines and jet engines by 7% and provide a combined primary energy saving of 18-20 quads of energy by 2050.