Thermal Diffusion in Carbon/Carbon Composites.

Abstract

Transient heat flow through carbon/carbon materials was studied. It was found that special steps must be taken to measure thermal diffusivity along the principal axes, especially at temperatures below about 500 C. However, the use of off-axis samples permitted the unambigious determination of diffusivity values, not only in the off-axis directions, but also along the principal axes. Diffusivity results for the matrix and for the fiber bundles were also obtained directly and indirectly and the results were in reasonable agreement. It was shown that there is a surface layer in carbon/carbon materials in which inter-constituent thermal gradients are significant and beyond which they are negligible. Carbon/carbon materials may be treated as homogeneous through regions which are much thicker than the heterogeneity dimension but in surface layers subjected to large heat fluxes, the heterogeneity must be considered. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1982
Accession Number
ADA121491

Entities

People

  • H. Groot
  • J. Jortner
  • R. E. Taylor

Tags

Communities of Interest

  • Sensors
  • Weapons Technologies

DTIC Thesaurus Topics

  • Carbon Carbon Composites
  • Composite Materials
  • Crystal Structure
  • Detectors
  • Diffusivity
  • Equations
  • Fibers
  • Heat Transfer
  • Heat Transmission
  • Materials
  • Materials Testing
  • Temperature Gradients
  • Thermal Conductivity
  • Thermal Diffusion
  • Thermal Diffusivity
  • Thermophysical Properties
  • Three Dimensional

Readers

  • Materials Science and Engineering.
  • Reinforced Composite Materials
  • Thermal Physics or Thermal Science.