Thermal barrier coatings design with increased reflectivity and lower thermal conductivity for high-temperature turbine applications

Matthew J. Kelly, Douglas E. Wolfe, Jogender Singh, Jeff Eldridge, Dong Ming Zhu, Robert Miller

Research output: Contribution to journalArticle

54 Citations (Scopus)

Abstract

High reflectance thermal barrier coatings consisting of 7% Yittria-Stabilized Zirconia (7YSZ) and Al2O3 were deposited by co-evaporation using electron beam physical vapor deposition (EB-PVD). Multilayer 7YSZ and Al2O3 coatings with fixed layer spacing showed a 73% infrared reflectance maxima at 1.85 mm wavelength. The variable 7YSZ and Al2O3 multilayer coatings showed an increase in reflection spectrum from 1 to 2.75 mm. Preliminary results suggest that coating reflectance can be tailored to achieve increased reflectance over a desired wavelength range by controlling the thickness of the individual layers. In addition, microstructural enhancements were also used to produce low thermal conductive and high hemispherical reflective thermal barrier coatings (TBCs) in which the coating flux was periodically interrupted creating modulated strain fields within the TBC. TBC showed no macrostructural differences in the grain size or faceted surface morphology at low magnification as compared with standard TBC. The residual stress state was determined to be compressive in all of the TBC samples, and was found to decrease with increasing number of modulations. The average thermal conductivity was shown to decrease approximately 30% from 1.8 to 1.2 W/m-K for the 20-layer monolithic TBC after 2 h of testing at 1316°C. Monolithic modulated TBC also resulted in a 28% increase in the hemispherical reflectance, and increased with increasing total number of modulations.

Original languageEnglish (US)
Pages (from-to)81-93
Number of pages13
JournalInternational Journal of Applied Ceramic Technology
Volume3
Issue number2
DOIs
StatePublished - Mar 1 2006

Fingerprint

Thermal barrier coatings
turbines
Thermal conductivity
Turbines
thermal conductivity
reflectance
coatings
Zirconia
Coatings
Temperature
zirconium oxides
Multilayers
Modulation
Reflective coatings
Wavelength
Physical vapor deposition
Surface morphology
modulation
Electron beams
Residual stresses

All Science Journal Classification (ASJC) codes

  • Ceramics and Composites
  • Condensed Matter Physics
  • Marketing
  • Materials Chemistry

Cite this

@article{5660bd38a4164841bf07f0d8c6668a72,
title = "Thermal barrier coatings design with increased reflectivity and lower thermal conductivity for high-temperature turbine applications",
abstract = "High reflectance thermal barrier coatings consisting of 7{\%} Yittria-Stabilized Zirconia (7YSZ) and Al2O3 were deposited by co-evaporation using electron beam physical vapor deposition (EB-PVD). Multilayer 7YSZ and Al2O3 coatings with fixed layer spacing showed a 73{\%} infrared reflectance maxima at 1.85 mm wavelength. The variable 7YSZ and Al2O3 multilayer coatings showed an increase in reflection spectrum from 1 to 2.75 mm. Preliminary results suggest that coating reflectance can be tailored to achieve increased reflectance over a desired wavelength range by controlling the thickness of the individual layers. In addition, microstructural enhancements were also used to produce low thermal conductive and high hemispherical reflective thermal barrier coatings (TBCs) in which the coating flux was periodically interrupted creating modulated strain fields within the TBC. TBC showed no macrostructural differences in the grain size or faceted surface morphology at low magnification as compared with standard TBC. The residual stress state was determined to be compressive in all of the TBC samples, and was found to decrease with increasing number of modulations. The average thermal conductivity was shown to decrease approximately 30{\%} from 1.8 to 1.2 W/m-K for the 20-layer monolithic TBC after 2 h of testing at 1316°C. Monolithic modulated TBC also resulted in a 28{\%} increase in the hemispherical reflectance, and increased with increasing total number of modulations.",
author = "Kelly, {Matthew J.} and Wolfe, {Douglas E.} and Jogender Singh and Jeff Eldridge and Zhu, {Dong Ming} and Robert Miller",
year = "2006",
month = "3",
day = "1",
doi = "10.1111/j.1744-7402.2006.02073.x",
language = "English (US)",
volume = "3",
pages = "81--93",
journal = "International Journal of Applied Ceramic Technology",
issn = "1546-542X",
publisher = "Wiley-Blackwell",
number = "2",

}

Thermal barrier coatings design with increased reflectivity and lower thermal conductivity for high-temperature turbine applications. / Kelly, Matthew J.; Wolfe, Douglas E.; Singh, Jogender; Eldridge, Jeff; Zhu, Dong Ming; Miller, Robert.

In: International Journal of Applied Ceramic Technology, Vol. 3, No. 2, 01.03.2006, p. 81-93.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Thermal barrier coatings design with increased reflectivity and lower thermal conductivity for high-temperature turbine applications

AU - Kelly, Matthew J.

AU - Wolfe, Douglas E.

AU - Singh, Jogender

AU - Eldridge, Jeff

AU - Zhu, Dong Ming

AU - Miller, Robert

PY - 2006/3/1

Y1 - 2006/3/1

N2 - High reflectance thermal barrier coatings consisting of 7% Yittria-Stabilized Zirconia (7YSZ) and Al2O3 were deposited by co-evaporation using electron beam physical vapor deposition (EB-PVD). Multilayer 7YSZ and Al2O3 coatings with fixed layer spacing showed a 73% infrared reflectance maxima at 1.85 mm wavelength. The variable 7YSZ and Al2O3 multilayer coatings showed an increase in reflection spectrum from 1 to 2.75 mm. Preliminary results suggest that coating reflectance can be tailored to achieve increased reflectance over a desired wavelength range by controlling the thickness of the individual layers. In addition, microstructural enhancements were also used to produce low thermal conductive and high hemispherical reflective thermal barrier coatings (TBCs) in which the coating flux was periodically interrupted creating modulated strain fields within the TBC. TBC showed no macrostructural differences in the grain size or faceted surface morphology at low magnification as compared with standard TBC. The residual stress state was determined to be compressive in all of the TBC samples, and was found to decrease with increasing number of modulations. The average thermal conductivity was shown to decrease approximately 30% from 1.8 to 1.2 W/m-K for the 20-layer monolithic TBC after 2 h of testing at 1316°C. Monolithic modulated TBC also resulted in a 28% increase in the hemispherical reflectance, and increased with increasing total number of modulations.

AB - High reflectance thermal barrier coatings consisting of 7% Yittria-Stabilized Zirconia (7YSZ) and Al2O3 were deposited by co-evaporation using electron beam physical vapor deposition (EB-PVD). Multilayer 7YSZ and Al2O3 coatings with fixed layer spacing showed a 73% infrared reflectance maxima at 1.85 mm wavelength. The variable 7YSZ and Al2O3 multilayer coatings showed an increase in reflection spectrum from 1 to 2.75 mm. Preliminary results suggest that coating reflectance can be tailored to achieve increased reflectance over a desired wavelength range by controlling the thickness of the individual layers. In addition, microstructural enhancements were also used to produce low thermal conductive and high hemispherical reflective thermal barrier coatings (TBCs) in which the coating flux was periodically interrupted creating modulated strain fields within the TBC. TBC showed no macrostructural differences in the grain size or faceted surface morphology at low magnification as compared with standard TBC. The residual stress state was determined to be compressive in all of the TBC samples, and was found to decrease with increasing number of modulations. The average thermal conductivity was shown to decrease approximately 30% from 1.8 to 1.2 W/m-K for the 20-layer monolithic TBC after 2 h of testing at 1316°C. Monolithic modulated TBC also resulted in a 28% increase in the hemispherical reflectance, and increased with increasing total number of modulations.

UR - http://www.scopus.com/inward/record.url?scp=33645521017&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33645521017&partnerID=8YFLogxK

U2 - 10.1111/j.1744-7402.2006.02073.x

DO - 10.1111/j.1744-7402.2006.02073.x

M3 - Article

AN - SCOPUS:33645521017

VL - 3

SP - 81

EP - 93

JO - International Journal of Applied Ceramic Technology

JF - International Journal of Applied Ceramic Technology

SN - 1546-542X

IS - 2

ER -