E噩≈S Journal of the European Ceramic Society 22(2002)2769-2775 www.elsevier.com/locate/jeurceramsoc Evaluation of CFCC liners with EBC after field testing in a gas turbine Josh Kimmela, * Narendernath Miriyalaa, Jeffrey Pricea, Karren More Peter Tortorelli, Harry Eaton Gary Linsey, Ellen Sun corporated, San Diego, CA, US.A bOak Ridge National Laboratory, Oak Ridge, TN, USA United Technologies Research Center, East Hartford, CT, US/ Received 21 October 2001; received in revised form I February 2002: accepted 25 February 2002 Abstract Under the Ceramic Stationary Gas Turbine(CSGT) Program sponsored by the U. s. Department of Energy(doe), a team led by Solar Turbines Incorporated has successfully designed engines, utilizing silicon carbide/silicon carbide(SiC/Sic)continuous fiber-reinforced ceramic composite(CFCC) combustor liners. Their potential for low NO and CO emissions was demonstrated ht field-engine tests for a total duration of more than 35,000 h. In the first four field tests, the durability of the liners was limited primarily by the long-term stability of Sic in the high steam environment of the gas turbine combustor. Consequently, the need for an environmental barrier coating(EBC) to meet the 30,000-h life goal was recognized. An eBC developed under the National Aeronautics and Space Administration high speed civil transport, enabling propulsion materials program was improved and opti- mized under the CsGT program and applied on the Sic/SiC liners by United Technologies Research Center (UTRC) from the fifth field test onwards. The evaluation of the EBC on SiC/SiC liners after the fifth field test with 13, 937-h at Texaco, Bakersfield, CA, USA is presented in this paper. C 2002 Elsevier Science Ltd. All rights reserved Keywords: Composites; EBC; Electron microscopy; Engine components; SiC 1. Introduction Engine tests were performed at two sites: Texaco (Bakersfield, CA, USA)and Malden Mills(Lawrence In pursuance of its mission to conserve the nations MA, USA). Since July 2000, the field tests are being nergy resources and reduce environmental pollution, performed under the Advanced Materials Program the U.S. Department of Energy, Office of Industrial sponsored by the DOE's Office of Power Technologies Technologies, initiated a program in 1992 to develop SiC/Sic CFCC combustor liners were tested in Solars and demonstrate a ceramic stationary gas turbine for Centaur 50s industrial gas turbine with a nominal power-and-steam cogeneration operation. Solar Tur- power output of 4 MWe. To date, five field tests bines Incorporated (Solar) is the prime contractor on were completed at the Texaco site and one at Malden the program, with participation from major ceramic Mills. A second test at Malden Mills, and a sixth test at component suppliers, research laboratories and two Texaco are currently in progress. I ndustrial end users. The main objective of the program a high rate of SiC recession was exhibited on the is to demonstrate ceramic technology by selective repla- CFCC liners in the first four engine tests due to volati cement of cooled metallic hot-section components by lization of Sic in a combustion environment. In the ceramic parts(blades, nozzles and combustor liners). fourth field test at Texaco, up to 80% of wall thicknes The focus of this paper is on the evaluation of the ebc reduction was exhibited in some areas with localized hot on engine tested Sic/SiC CFCC combustor liners spots, after only 5028 h 1.2 Silicon-based materials such as sic are limited by Corresponding author. Tel: +1-619-544-2819; fax: +1-619-544- their poor environmental durability in combustion environments. SiC is known to perform very well in E-mailaddresskimmel_josh_b@solarturbines.com(.Kimmel).oxidationenvironmentsbyformingaslowgrowing 0955-2219/02/S- see front matter C 2002 Elsevier Science Ltd. All rights reserved. PII:S0955-2219(02)00142-5Evaluation of CFCC liners with EBC after field testing in a gas turbine Josh Kimmela,*, Narendernath Miriyalaa , Jeffrey Pricea , Karren Moreb, Peter Tortorellib, Harry Eatonc , Gary Linseyc , Ellen Sunc a Solar Turbines Incorporated, San Diego, CA, USA bOak Ridge National Laboratory, Oak Ridge, TN, USA c United Technologies Research Center, East Hartford, CT, USA Received 21 October 2001; received in revised form 1 February 2002; accepted 25 February 2002 Abstract Under the Ceramic Stationary Gas Turbine (CSGT) Program sponsored by the U.S. Department of Energy (DOE), a team led by Solar Turbines Incorporated has successfully designed engines, utilizing silicon carbide/silicon carbide (SiC/SiC) continuous fiber-reinforced ceramic composite (CFCC) combustor liners. Their potential for low NOx and CO emissions was demonstrated in eight field-engine tests for a total duration of more than 35,000 h. In the first four field tests, the durability of the liners was limited primarily by the long-term stability of SiC in the high steam environment of the gas turbine combustor. Consequently, the need for an environmental barrier coating (EBC) to meet the 30,000-h life goal was recognized. An EBC developed under the National Aeronautics and Space Administration high speed civil transport, enabling propulsion materials program was improved and opti￾mized under the CSGT program and applied on the SiC/SiC liners by United Technologies Research Center (UTRC) from the fifth field test onwards. The evaluation of the EBC on SiC/SiC liners after the fifth field test with 13,937-h at Texaco, Bakersfield, CA, USA is presented in this paper. # 2002 Elsevier Science Ltd. All rights reserved. Keywords: Composites; EBC; Electron microscopy; Engine components; SiC 1. Introduction In pursuance of its mission to conserve the nation’s energy resources and reduce environmental pollution, the U.S. Department of Energy, Office of Industrial Technologies, initiated a program in 1992 to develop and demonstrate a ceramic stationary gas turbine for power-and-steam cogeneration operation. Solar Tur￾bines Incorporated (Solar) is the prime contractor on the program, with participation from major ceramic component suppliers, research laboratories and two industrial end users. The main objective of the program is to demonstrate ceramic technology by selective repla￾cement of cooled metallic hot-section components by ceramic parts (blades, nozzles and combustor liners). The focus of this paper is on the evaluation of the EBC on engine tested SiC/SiC CFCC combustor liners. Engine tests were performed at two sites: Texaco (Bakersfield, CA, USA) and Malden Mills (Lawrence, MA, USA). Since July 2000, the field tests are being performed under the Advanced Materials Program sponsored by the DOE’s Office of Power Technologies. SiC/SiC CFCC combustor liners were tested in Solar’s Centaur 50S industrial gas turbine with a nominal power output of 4 MWe. To date, five field-engine tests were completed at the Texaco site and one at Malden Mills. A second test at Malden Mills, and a sixth test at Texaco are currently in progress.1 A high rate of SiC recession was exhibited on the CFCC liners in the first four engine tests due to volati￾lization of SiC in a combustion environment. In the fourth field test at Texaco, up to 80% of wall thickness reduction was exhibited in some areas with localized hot spots, after only 5028 h.1,2 Silicon-based materials such as SiC are limited by their poor environmental durability in combustion environments. SiC is known to perform very well in oxidation environments by forming a slow growing, 0955-2219/02/$ - see front matter # 2002 Elsevier Science Ltd. All rights reserved. PII: S0955-2219(02)00142-5 Journal of the European Ceramic Society 22 (2002) 2769–2775 www.elsevier.com/locate/jeurceramsoc * Corresponding author. Tel.: +1-619-544-2819; fax: +1-619-544- 2830. E-mail address: kimmel_josh_b@solarturbines.com (J. Kimmel)