Oxidation of Zirconium Diboride–Silicon Carbide at 1500°C at a Low Partial Pressure of Oxygen

Authors

  • Alireza Rezaie,

    1. Department of Materials Science and Engineering, University of Missouri Rolla, Rolla, Missouri 65409
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    • *Member, American Ceramic Society.

  • William G. Fahrenholtz,

    Corresponding author
    1. Department of Materials Science and Engineering, University of Missouri Rolla, Rolla, Missouri 65409
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    • *Member, American Ceramic Society.

  • Gregory E. Hilmas

    1. Department of Materials Science and Engineering, University of Missouri Rolla, Rolla, Missouri 65409
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    • *Member, American Ceramic Society.


  • N. Jacobson—contributing editor

  • This material is based upon work supported by the National Science Foundation under grant number DMR–0346800.

†Author to whom correspondence should be addressed. e-mail: billf@umr.edu

Abstract

The oxidation behavior of zirconium diboride containing 30 vol% silicon carbide particulates was investigated under reducing conditions. A gas mixture of CO and ∼350 ppm CO2 was used to produce an oxygen partial pressure of ∼10−10 Pa at 1500°C. The kinetics of the growth of the reaction layer were examined for reaction times of up to 8 h. Microstructures and chemistries of reaction layers were characterized using scanning electron microscopy and X-ray diffraction analysis. The kinetic measurements, the microstructure analysis, and a thermodynamic model indicate that oxidation in CO–CO2 produced a non-protective oxide surface scale.

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