Chapter 72. Thermal Barrier Coated Nextel 720 Fiber/Mullite Matrix Composites: Their Potential for Long-Term High Temperature Use in Gas Turbines

  1. Todd Jessen and
  2. Ersan Ustundag
  1. J. Goering,
  2. B. Kanka,
  3. U. Steinhauser and
  4. H. Schneider

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294628.ch72

24th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 21, Issue 3

24th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 21, Issue 3

How to Cite

Goering, J., Kanka, B., Steinhauser, U. and Schneider, H. (2000) Thermal Barrier Coated Nextel 720 Fiber/Mullite Matrix Composites: Their Potential for Long-Term High Temperature Use in Gas Turbines, in 24th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 21, Issue 3 (eds T. Jessen and E. Ustundag), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294628.ch72

Author Information

  1. Institute for Materials Research German Aerospace Center (DLR), D-51147 Koeln, Germany

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2000

ISBN Information

Print ISBN: 9780470375686

Online ISBN: 9780470294628

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Keywords:

  • tetragonal zirconia polycrystal/alumina composites;
  • surface modification;
  • infiltration method;
  • mullite;
  • liquid precursur infiltration

Summary

Continuous oxide fiber/oxide matrix composites have a high potential as thermal protection systems (TPS) for long-term high temperature applications in aircraft engines and stationary gas turbines. 1D-and 2D-composites have been developed based on highly porous mullite matrices and Nextel 720 alumina silicate fibers. These composites require no interface between fibers and matrix, and exhibit high resistance against thermal shock, excellent non-brittle fracture behavior, and favorable strength values (about 200 MPa) up to 1200°C.

The factor, limiting the application of the composites is the mechanical stability of Nextel 720 fibers at high temperatures. According to single fiber tensile tests extensive subcritical crack growth and creep deformation does occur at T>1000°C. The application temperature of the oxide/oxide composites, however, can considerably be increased by flame spray-deposited mullite layers on the hot site of the oxide/oxide substrates (> 100°C per mm layer thickness). Thermal and elastic misfits between thermal protection systems (TPS) and ceramic matrix composite substrate (CMC) are low, due to their similar phase compositions.