0

Full Content is available to subscribers

Subscribe/Learn More  >

Evaluating the Stability of BSAS-Based EBCs in High Water-Vapor Pressure Environments

[+] Author Affiliations
Karren L. More, Peter F. Tortorelli

Oak Ridge National Laboratory, Oak Ridge, TN

Tania Bhatia, G. D. Linsey

United Technologies Research Center, East Hartford, CT

Paper No. GT2004-53863, pp. 377-384; 8 pages
doi:10.1115/GT2004-53863
From:
  • ASME Turbo Expo 2004: Power for Land, Sea, and Air
  • Volume 2: Turbo Expo 2004
  • Vienna, Austria, June 14–17, 2004
  • Conference Sponsors: International Gas Turbine Institute
  • ISBN: 0-7918-4167-7 | eISBN: 0-7918-3739-4
  • Copyright © 2004 by ASME

abstract

Barium Strontium Aluminosilicate (BSAS)-based environmental barrier coatings (EBCs) have been used successfully to protect the surface of Si-based fiber-reinforced ceramic-matrix composite (CMC) combustor liners in Solar Turbines Centaur 50S gas turbine engines. Two such EBC/CMC combustor liner sets were engine-exposed for times > 14,000h. However, extensive microstructural characterization of the EBC/CMC liners after the long-term engine exposures showed a significant loss/recession of the BSAS-based EBC. The mechanisms by which BSAS recession occurs and the rate at which the BSAS recesses as a function of pressure, gas velocity, temperature, etc. are not fully understood but such information will be necessary for improving the life to >15,000h in order for the materials to be acceptable for use in an engine application. To this end, the thermochemical stabilities of candidate EBCs are being evaluated analytically and experimentally at very high H2 O pressures in a high-temperature, high-pressure furnace (Oak Ridge National Laboratory’s “Keiser Rig”). Calculations based on generalized volatility reactions and mass flux of volatilized species have shown that high H2 O pressures can be used to compensate for the low gas-flow velocities in the Keiser Rig. An examination of the phase stability/volatilization of state-of-the-art EBC compositions (Ba- and Sr-based aluminosilicates) has been conducted through equilibrium thermodynamic calculations and initial experiments to validate assumptions via Keiser Rig exposures of the same EBC formulations conducted at 1250°C and 20 atm H2 O.

Copyright © 2004 by ASME

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In