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2003 R&D 100 Award—CF8C-Plus
CF8C-Plus was designed to drastically improve high-temperature durability, performance and reliability based on ORNL's unique engineered microstructure alloy development methodology. The engineered microstructure method dramatically changes CF8C-Plus from steel that cannot be used above 600-650 degrees Celsius to steel that can be used up to 850 degrees Celsius and resists failure during creep, mechanical fatigue and thermal fatigue. Developers said that end users like Caterpillar or commercial foundries like MetalTek will benefit from CF8C-Plus because it is a cost-effective product with higher performance and immense reliability.
The new cast stainless steel for high-temperature performance, was developed and submitted jointly by Philip Maziasz and Robert Swindeman of ORNL's Metals and Ceramics Division and Caterpillar of Peoria, Ill. Joint developers are Timothy McGreevy, Bradley University; Paul Browning, Solar Turbines - DeSoto Overhaul Facility of DeSoto, Texas; and Arun Bhattacharya of Solar Turbines - Materials and Processes Engineering of San Diego.
2002 R&D 100 Award—Turbine Vane Keeps Its Cool
Researchers have been attempting for years to replace hot section components of uncooled ceramic turbines with metallic superalloys. Their success would mean higher firing temperatures, reduced cooling air requirements, and improved energy efficiency.
To leap this temperature barrier, researchers developed the Actively Cooled Monolithic All-Ceramic High Pressure Turbine Vane with an environmental barrier coating. This cooled silicon nitride vane is capable of operating at temperatures a few hundred degrees higher than any superalloy, requiring less cooling air than cooled superalloys. This reduction in cooling air can be channeled to increase engine power output and/or to reduce emissions.
A research team from United Technologies Research Center, East Hartford, Conn.; United Technologies Pratt & Whitney, East Hartford; Industrial Ceramics Corp., Vancouver, Wash.; and Honeywell Ceramic Components, Torrance, Calif., implemented impingement cooling inside of the vane to put tension inside and compression on the outside.
2001 R&D 100 Award—Coatings Extend Turbine Performance
A key factor that limits gas turbine engine performance is the temperature capabilities of the metallic structural components in the engine hot section. It is generally agreed that upper temperature limits of metals have been reached. Ceramics exhibit superior high-temperature strength and durability, but silicon-based ceramics suffer from rapid surface recession in combustion environments due to reaction with corrosive species. Two new coatings—Silicon/Mullite/BSAS and Silicon/Mullite+BSAS/BSAS EBCs (Environmental Barrier Coatings)—protect silicon-based ceramics from harsh environmental attacks, most notably water vapor and molten salts. In combustion environments, the new coatings dramatically improve the performance of silicon-based ceramics and have accumulated 14,000 hrs of operation at ~1250°C. The coatings were developed by a team of researchers from NASA Glenn Research Center, Cleveland; Pratt & Whitney, East Hartford, Conn.; General Electric, Schenectady,
N.Y.; and Solar Turbines Inc., San Diego.
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