1. New Thermal Barrier Coatings Based on Pyrochlore/YSZ Double Layer Systems

  1. Dongming Zhu and
  2. Kevin Plucknett
  1. Robert Vaßen and
  2. Detlev Stöver

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291238.ch1

Advances in Ceramic Coatings and Ceramic-Metal Systems: Ceramic Engineering and Science Proceedings, Volume 26, Number 3

Advances in Ceramic Coatings and Ceramic-Metal Systems: Ceramic Engineering and Science Proceedings, Volume 26, Number 3

How to Cite

Vaßen, R. and Stöver, D. (2005) New Thermal Barrier Coatings Based on Pyrochlore/YSZ Double Layer Systems, in Advances in Ceramic Coatings and Ceramic-Metal Systems: Ceramic Engineering and Science Proceedings, Volume 26, Number 3 (eds D. Zhu and K. Plucknett), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291238.ch1

Author Information

  1. Institut für Werkstoffe und Verfahren der Energietechnik (IWV1) Forschungszentrum Jülich GmbH Jülich, 52425, Germany

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2005

ISBN Information

Print ISBN: 9781574982336

Online ISBN: 9780470291238

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Keywords:

  • pyrochlore;
  • zirconia;
  • tetragonal;
  • homogeneous;
  • spallation

Summary

Pyrochlore material La2Zr2O7 has been investigated with respect to an application as new thermal barrier coating (TBC) material. Coatings were produced by atmospheric plasma-spraying.

The materials have been applied as single layer coatings with only a topcoat made of pyrochlore material. In addition, also double layer systems with a first layer of yttria stabilized zirconia (YSZ) and on top a layer made of pyrochlore material were produced. These systems have been tested in thermal cycling test rigs at surface temperatures between 1200 and 1500°C and the results were compared to the behavior of standard YSZ coatings. The results indicated that single layer coatings had a rather poor thermal cycling performance. In contrast, the double layer systems performed at a medium temperatures range below about 1300°C similar to the YSZ coatings. At higher temperatures the double layer coatings revealed excellent thermal cycling behavior. Lifetime was at these test conditions by orders of magnitude better than the lifetime of YSZ coatings. Results indicate that an increase of the maximum surface temperature in gas turbines by at least 100 K becomes possible with the new coatings. The results also indicate that with a surface temperature of about 1450°C the limit of the temperature capability of La2Zr2O7/YSZ seems to be reached.