2. Mechanical and Thermal Properties of Advanced Oxide Materials for Higher-Temperature Coatings Applications

  1. Dongming Zhu and
  2. Kevin Plucknett
  1. Sung R. Choi,
  2. Narottam P. Bansal and
  3. Dongming Zhu

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291238.ch2

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

Choi, S. R., Bansal, N. P. and Zhu, D. (2005) Mechanical and Thermal Properties of Advanced Oxide Materials for Higher-Temperature Coatings Applications, 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.ch2

Author Information

  1. NASA Glenn Research Center, Cleveland, OH 44135

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:

  • thermal;
  • combustion;
  • magnetoplumbite;
  • diameter;
  • microhdness

Summary

Advanced oxide material systems are being developed for higher-temperature thermaiyenvironmental barrier coatings (T/EBCs) in advanced gas turbine engine applications. Four pyrochlore oxide (La2Zr2O7, Nd2Zr2O7, Gd2Zr2O7, and La2Hf2O7) and three magnetoplumbite oxide (LaMnAl11O19, LaMgAl11O19, and LaZnAl11O19) powders were hot pressed. Ambient-temperature mechanical properties of these oxides including flexure strength, fracture toughness, elastic modulus, and hardness were determined. Thermal properties such as thermal conductivity, coefficient of thermal expansion, and environmental durability were also determined. LaMgAl11O19 and LaZnAl11O19 exhibited higher strength (>300 MPa) and higher fracture toughness (> 3 MPa√m) than the other oxides that exhibited strength of 40-150 MPa and fracture toughness of 1-2 MPa√m. Despite their poor ambient-temperature mechanical properties, certain pyrochlore oxides showed promising results over other oxides as coating materials in view of low thermal conductivity, good creep resistance and good water vapor stability in combustion environments.