72. Characterization of Y2O3-Doped La2Zr2O7 Based EB-PVD Thermal Barrier Coatings Using X-Ray Microtomography (CMT) and Small Angle Neutron Scattering (SANS)

  1. Edgar Lara-Curzio and
  2. Michael J. Readey
  1. B. Saruhan1,
  2. A. Flores Renteria1,
  3. F. Decarlo2,
  4. A. Kulkarni3 and
  5. J. Ilavsky4

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291191.ch72

28th International Conference on Advanced Ceramics and Composites B: Ceramic Engineering and Science Proceedings, Volume 25, Issue 4

28th International Conference on Advanced Ceramics and Composites B: Ceramic Engineering and Science Proceedings, Volume 25, Issue 4

How to Cite

Saruhan, B., Renteria, A. F., Decarlo, F., Kulkarni, A. and Ilavsky, J. (2004) Characterization of Y2O3-Doped La2Zr2O7 Based EB-PVD Thermal Barrier Coatings Using X-Ray Microtomography (CMT) and Small Angle Neutron Scattering (SANS), in 28th International Conference on Advanced Ceramics and Composites B: Ceramic Engineering and Science Proceedings, Volume 25, Issue 4 (eds E. Lara-Curzio and M. J. Readey), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291191.ch72

Author Information

  1. 1

    Institute of Materials Research DLR German Aerospace Center 51170 Cologne, Germany

  2. 2

    Advanced Photon Source Argonne National Laboratory Argonne, IL 60439, USA

  3. 3

    Dept. of Materials Sci. and Eng. University at Stony Brook Stony Brook; NY 11794-2275, USA

  4. 4

    Purdue University West Lafayette, ID, 47907, USA

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2004

ISBN Information

Print ISBN: 9780470051528

Online ISBN: 9780470291191

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Keywords:

  • thermal barrier coatings;
  • high-energy x-ray;
  • gas turbine engine;
  • yittria-stabilized zirconia;
  • transmission geometry

Summary

Thermal degradation of the Partially Yttria Stabilized Zirconia (PYSZ)-based Thermal Barrier Coatings (TBCs) brought up the consideration of new coating compositions. The requirement is that these show high phase and microstructure stability at temperatures above 1200°C. The group of pyrochlore-structured oxide compounds is one of those new compositions, which may offer more advantageous properties and, thus replace the standard-material 8YSZ (8 wt. % Y2O3 stabilized ZrO2). These compounds with AxByOz composition offer lower thermal and ionic conductivity, comparable thermal expansion coefficient to 8YSZ and display more stable phase structure and morphology at the temperatures up to 1400°C, relying on their cubic pyrochlore structure.

This paper reports the EB-PVD-processing of single phase pyrochlore (La2Zr2O7) coatings, undoped and doped with 3 and 10 wt.% Y2O3. Coatings are characterized using high-resolution synchrotron-based computerised x-ray microtomography (CMT), small angle neutron diffraction (SAND) and by scanning electron microscope (SEM) and results are compared with standard 8YSZ coatings. Experiments focus on quantitative characterization/visualization of imperfections in these coatings and on relative changes in microstructural features upon isothermal annealing. Results present an insight into sintering mechanisms in these coatings.