Chapter 57. Mechanical Properties of an Environmental Barrier Coating on a Monolithic SiC Substrate and Its Role on Substrate Failure Behavior

  1. Hau-Tay Lin and
  2. Mrityunjay Singh
  1. Shanti V. Nair1,
  2. Harry E. Eaton2,
  3. Ellen Y. Sun2 and
  4. Greg C. Ojard2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294758.ch57

26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: B: Ceramic Engineering and Science Proceedings, Volume 23, Issue 4

26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: B: Ceramic Engineering and Science Proceedings, Volume 23, Issue 4

How to Cite

Nair, S. V., Eaton, H. E., Sun, E. Y. and Ojard, G. C. (2008) Mechanical Properties of an Environmental Barrier Coating on a Monolithic SiC Substrate and Its Role on Substrate Failure Behavior, in 26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: B: Ceramic Engineering and Science Proceedings, Volume 23, Issue 4 (eds H.-T. Lin and M. Singh), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294758.ch57

Author Information

  1. 1

    Department of Mechanical and Industrial Engineering University of Massachusetts at Amherst Amherst, MA 01003–2210

  2. 2

    United Technologies Research Center 411 Silver Lane East Hartford, CT 06108

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2002

ISBN Information

Print ISBN: 9780470375792

Online ISBN: 9780470294758

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Keywords:

  • environmental barrier coatings;
  • monolithic sic substrate;
  • coating modules;
  • ceramics;
  • modulus measurement

Summary

The stress capability of a multilayer elastic environmental barrier coating on Hexoly SiC ceramic was characterized by measuring the coating modulus and failure strains. Next the influence of the coating on the failure behavior of the substrate Hexolly ceramic was determined for each of the three individual layers that constitute the coating. It was found that the Si bond coat demonstrated substantial stress capability with a modulus on the order of 137 GPa, close to that of a theoretically fully dense Si with failure strains on the order of 1100 microstrain. The bond coat appeared to dominate the modulus of the the overall coating. The coating was found to increase both the strength and Weibull modulus of the SiC ceramic. The enhanced failure resistance is attributed to the role of the coating in altering the effective flaw size and the flaw size distribution in the coated ceramic. The Si bond coat also dominated the other layers in terms of its effect on the strength and the Weibull modulus of the SiC.