Temperatures of hot section components in today’s gas turbine engines reach as high as 1,500 °C, making in situ monitoring of the severe temperature gradients within the engine rather difficult. Therefore, there is a need to develop instrumentation ( i.e., thermocouples and strain gauges) for these turbine engines that can survive these harsh environments. Refractory metal and ceramic thin film thermocouples are well suited for this task since they have excellent chemical and electrical stability at high temperatures in oxidizing atmospheres, they are compatible with thermal barrier coatings commonly employed in today’s engines, they have greater sensitivity than conventional wire thermocouples, and they are non-invasive to combustion aerodynamics in the engine. Thin film thermocouples based on platinum:palladium and indium oxynitride:indium tin oxynitride as well as their oxide counterparts have been developed for this purpose and have proven to be more stable than conventional type-S and type-K thin film thermocouples. The metallic and ceramic thin film thermocouples described within this paper exhibited remarkable stability and drift rates similar to bulk (wire) thermocouples.
References
[1]
Wrbanek, J.D.; Fralick, G.C.; Zhu, D. Ceramic thin film thermocouples for SiC-based ceramic matrix composites. Thin Solid Film 2012, 520, 5801–5806.
[2]
Aniolek, G.E.; Gregory, O.J. Thin film thermocouples for advanced ceramic gas turbine engines. Surf. Coat. Technol. 1994, 68–69, 70–75.
[3]
Lei, J.F.; Will, H.A. Thin-film thermocouples and strain-gauge technologies for engine applications. Sens. Actuator A 1998, 65, 187–193.
[4]
Martin, L.C.; Holanda, R. Applications of Thin-Film Thermocouples for Surface Temperature Measurement. Proceedings of NASA/SPIE Conference on Spin-Off Technologies from NASA for Commercial Sensors and Scientific Applications, San Diego, CA, USA, 25–26 July 1994; pp. 1–12.
[5]
Gregory, O.J.; Amani, M.; Tougas, I.M.; Drehman, A.J. Stability and microstructure of indium tin oxynitride thin films. J. Am. Ceram. Soc. 2012, 95, 705–710.
[6]
Kreider, K.G. Sputtered high temperature thin film thermocouples. J. Vac. Sci. Technol. 1993, 11, 1401–1405.
[7]
Hill, K.D. An investigation of palladium oxidation in the platinum-palladium thermocouple system. Metrologia 2002, 39, 51–58.
[8]
Ahmed, M.G.; Ali, K. Investigating Pt-Pd Thermocouples in the Temperature Range from 800 °C to 1,500 °C at the National Institute of Standards NIS-Egypt. J. Metrol. Soc. India 2008, 23, 225–230.
[9]
Burns, G.W.; Ripple, D.C.; Battuello, M. Platinum versus palladium thermocouples—An emf-temperature reference function for the range 0 °C to 1,500 °C. Metrologia 1998, 35, 761–780.
[10]
Abdelaziz, Y.A.; Megahed, F.M.; Halawa, M.M. Stability and calibration of platinum-palladium thermocouples following heat treatment. Measurement 2004, 35, 413–420.
[11]
Moiseeva, N.P. The prospect for developing standard thermocouples of pure metals. Meas. Sci. Technol. 2004, 47, 915–919.
[12]
Kreider, K.G.; Gillen, G. High temperature materials for thin-film thermocouples on silicon wafers. Thin Solid Film 2000, 376, 32–37.
[13]
Kreider, K.G.; DiMeo, F. Platinum-palladium thin-film thermocouples for temperature measurements on silicon wafers. Sens. Actuator A 1998, 69, 46–52.
[14]
Choi, H.; Li, X. Fabrication and application of micro thin film thermocouples for transient temperature measurement in nanosecond pulsed laser micromachining of nickel. Sens. Actuator A 2007, 136, 118–124.
[15]
Bentley, R.E. Theory and Practice of Thermoelectric Thermometry. In Handbook of Temperature Measurement; Springer: New York, NY, USA, 1998; Volume Vol. 3.
[16]
Tougas, I.M.; Gregory, O.J. Thin film platinum-palladium thermocouples for gas turbine engine applications. Thin Solid Films 2013, 539, 345–349.
[17]
Gregory, O.J.; You, T. Piezoresistive properties of ITO strain sensors prepared with controlled nanoporosity. J. Electrochem. Soc. 2004, 151, 198–203.
[18]
Chen, X.; Gregory, O.J.; Amani, M. Thin-film thermocouples based on the system In2O3-SnO2. J. Am. Ceram. Soc. 2011, 94, 854–860.
[19]
Revised Thermocouple Reference Tables: Type S. Available online: http://www.omega.com/temperature/Z/pdf/z208–209.pdf (accessed on 23 March 2013).
[20]
Beszeda, I.; Gontier-Moya, E.G.; Beke, D.L. Investigation of mass transfer surface self-diffusion on palladium. Surf. Sci. 2003, 547, 229–238.
[21]
Jonker, G. The application of combined conductivity and Seebeck-effect plots for the analysis of semiconducting properties. Philips J. Res. 1968, 23, 131.
[22]
Medvedovski, E.; Szepesi, C.J.; Yankov, O.; Lippens, P. Indium tin oxide nanosized transparent conductive thin films obtained by sputtering from large size planar and rotary targets. Ceram. Trans. 2010, 223, 125–146.
[23]
Gegner, J.; H？rz, G.; Kirchheim, R. Diffusivity and solubility of oxygen in solid palladium. J. Mater. Sci. 2009, 44, 2198–2205.
[24]
Jehn, H. High temperature behavior of platinum group metals in oxidizing atmospheres. J. Less Common Met. 1984, 100, 321–339.
[25]
Chaston, J.C. The oxidation of the platinum metals—A descriptive survey of the reactions involved. Platin. Met. Rev. 1975, 19, 135–140.
[26]
Bharadwaj, S.R.; Kerkar, A.S.; Tripathi, S.N.; Dharwadkar, S.R. The palladium-platinum phase diagram. J. Less Common Met. 1991, 169, 167–172.
[27]
Gregory, O.J.; Chen, X.; Medvedovski, E.; Szepesi, C.J.; Yankov, O. Oxide Ceramic Semiconductors for High Temperature Thermoelectric Applications. Proceedings of 34th International Conference on Advances Ceramics and Composites, Daytona Beach, FL, USA, 24–29 January, 2010.
[28]
Gregory, O.J.; Lee, S.B.; Flagan, R.C. Reaction sintering of submicrometer silicon powder. J. Am. Ceram. Soc. 1987, 70, 52–55.
[29]
Varela, J.A.; Whittemore, O.J.; Longo, E. Pore size evolution during sintering of ceramic oxides. Ceram. Int. 1990, 16, 177–189.
[30]
Garino, T.J.; Bowen, H.K. Kinetics of constrained-film sintering. J. Am. Ceram. Soc. 1990, 73, 251–257.
[31]
Gregory, O.J.; Luo, Q.; Crisman, E.E. High temperature stability of indium tin oxide thin films. Thin Solid Film 2002, 406, 286–293.
[32]
Harvey, S.P.; Mason, T.O.; Gassenbauer, Y.; Schafranek, R.; Klein, A. Surface versus bulk electronic/defect structures of transparent conducting oxides: I. Indium oxide and ITO. J. Phys. D: Appl. Phys. 2006, 39, 3959–3968.
