Chapter 24. Microstructure and Mechanical Response of Lanthanum Phosphate/Yttrium Aluminate and Yttrium Phosphate/Yttrium Aluminate Systems

  1. John B. Wachtman Jr.
  1. Dong-Hau Kuo and
  2. Waltraud M. Kriven

Published Online: 28 MAR 2008

DOI: 10.1002/9780470314876.ch24

Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 17, Issue 4

Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 17, Issue 4

How to Cite

Kuo, D.-H. and Kriven, W. M. (2008) Microstructure and Mechanical Response of Lanthanum Phosphate/Yttrium Aluminate and Yttrium Phosphate/Yttrium Aluminate Systems, in Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 17, Issue 4 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314876.ch24

Author Information

  1. Department of Materials Science and Engineering The University of Illinois at Urbana-Champaign Urbana, IL 61801

Publication History

  1. Published Online: 28 MAR 2008
  2. Published Print: 1 JAN 1996

ISBN Information

Print ISBN: 9780470375433

Online ISBN: 9780470314876

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Keywords:

  • lanthanum phosphate;
  • tape-cast laminates;
  • interfacial delamination;
  • promising weak interface;
  • interfacial shear strength

Summary

The use of lanthanum phosphate (LaPO4) and yttrium phosphate (YPO4) as weak interfaces in composites for high temperature applications was investigated using tape-cast laminates. Interfacial delamination occurred in the YPO4/Y3Al5O12 laminate under mechanical tests. This laminate showed a promising weak interface, as compared with the LaPO4/Y3Al5O12 system.

The interfacial properties of a fiber model system, (viz., single crystal Y3Al5O12 (YAG) fiber/LaPO4 coating/Al2O3 matrix), as a function of coating thickness were evaluated by the fiber pushout test. Interfacial shear strength, frictional strength, mode II fracture energy, coefficient of friction, and clamping stress were obtained by curve-fitting the theoretical equations to the experimental data.