Chapter 11. Chromium-Aluminum Hydroxide Synthesis and Sintering of the Solid Solution CrxAl2_xO3

  1. William J. Smothers
  1. S. V. Raman1,
  2. R. H. Doremus2 and
  3. R. M. German2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470320358.ch11

Proceedings of the 13th Automotive Materials Conference: Ceramic Engineering and Science Proceedings, Volume 7, Issue 9/10

Proceedings of the 13th Automotive Materials Conference: Ceramic Engineering and Science Proceedings, Volume 7, Issue 9/10

How to Cite

Raman, S. V., Doremus, R. H. and German, R. M. (2008) Chromium-Aluminum Hydroxide Synthesis and Sintering of the Solid Solution CrxAl2_xO3, in Proceedings of the 13th Automotive Materials Conference: Ceramic Engineering and Science Proceedings, Volume 7, Issue 9/10 (ed W. J. Smothers), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470320358.ch11

Author Information

  1. 1

    Brookhaven National Laboratory Upton, NY 11973

  2. 2

    Rensselaer Polytechnic Inst. Troy, NY 12181

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1986

ISBN Information

Print ISBN: 9780470374689

Online ISBN: 9780470320358

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Keywords:

  • hydroxide synthesis;
  • solid solution;
  • densflcatfon;
  • shrinkage;
  • gel precipitatfon

Summary

Chromium-ahtminum hydroxide powders were prepared by gel precipitation in ethanol. Shrinkage and densiflcation of the original hydroxide compacts are activated by escape of vapor phase, transformation in the order, hydroxide-amorphous oxide—alpha allotrope, and valency change of Or. Relative to the hydroxide green compact, the density increases four-fold to a value of 98% theoretical at 1600°C. Enhanced diffusivity of the solute phase at a high temperature, like 1700°C, causes pore-grain boundary breakaway and concomitant desintering with 15% reduction in density.