Thermal expansion of pyrolytic carbon with various textures

Authors

  • W. Zhang,

    1. Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology (KIT), PF 6980, 76049 Karlsruhe, Germany
    2. Institute of Process Engineering, Chinese Academy of Sciences, 100190 Beijing, China
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  • A. Li,

    1. Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology (KIT), PF 6980, 76049 Karlsruhe, Germany
    2. Composite Materials Research Center, Shanghai University, 200072 Shanghai, China
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  • B. Reznik,

    1. Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology (KIT), PF 6980, 76049 Karlsruhe, Germany
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  • O. Deutschmann

    Corresponding author
    1. Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology (KIT), PF 6980, 76049 Karlsruhe, Germany
    2. Institute for Catalysis Research and Technology, Karlsruhe Institute of Technology (KIT), PF 6980, 76049 Karlsruhe, Germany
    • Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology (KIT), PF 6980, 76049 Karlsruhe, Germany
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    • Tel.: +49 721 60843064, Fax: +49 721 60844805


Abstract

Thermal expansion of differently-textured pyrolytic carbon matrices (pyrocarbons) of carbon/carbon composites was studied with a high temperature X-ray diffraction at temperatures ranging from 25°C to 1400°C. The composites were synthesized by chemical vapor infiltration of a carbon fiber felt, using methane as a carbon source. From the linear dependence of the lattice displacement on temperature, coefficients of thermal expansion (CTE) of the pyrocarbons were calculated. One-dimensional thermal expansion along the (002)-direction (c-axis) of the pyrocarbons was found to be proportional to the composite synthesis temperature. A correlation between CTE and pyrocarbon texture was found: low-textured pyrocarbon with an extinction angle (Ae) of 10° exhibits a smaller CTE of 2.02 × 10-5 K-1, whereas high-textured pyrocarbon with an Ae of 22° exhibits a considerably higher CTE of 2.65 × 10-5 K-1. However, CTE of high-textured pyrocarbon is still smaller than that of graphite, which is 2.9 ×10-5 K-1.

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