Advertisement

Effect of Micro-Cracking on Thermal Conductivity: Analysis and Experiment

  • D. P. H. Hasselman

Abstract

High densities of micro-cracks can have a profound effect on the conduction of heat through materials. An analysis of this effect on thermal conductivity is presented. The variables which affect the formation of micro-cracks in brittle materials due to thermal expansion mismatches are discussed. It is shown that micro-cracking results in a “thermo-mechanically” coupled thermal conductivity which is a function of elastic properties, the coefficient of thermal expansion, fracture toughness, microstructural variables such as grain size, as well as the closure and healing of cracks at higher temperatures These effects are demonstrated by experimental data for the temperature dependence of the thermal diffusivity of polycrystalline iron titanate, magnesium dititanate, composites of alumina with silicon carbide, and a glass containing a dispersed phase of nickel.

Keywords

Thermal Conductivity Thermal Diffusivity Brittle Material Crack Closure Thermal Expansion Mismatch 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    R. C. Rossi, Bull. Amer. Ceram. Soc., 48 (1969) 736.Google Scholar
  2. 2.
    D. P. H. Hasselman, J. Amer. Ceram. Soc., 52 (1969) 600.CrossRefGoogle Scholar
  3. 3.
    R. L. Salganik, Izv. An. SSSR, Mekhanika Tverdogo Tela, 8 (1973) 149.Google Scholar
  4. 4.
    B. Budiansky and R. J. O’Connell, Int. J. Solid Structures, 12 (1976) 8.CrossRefGoogle Scholar
  5. 5.
    J. A. Kuszyk and R. C. Bradt, J. Amer. Ceram. Soc., 56 (1973) 420.CrossRefGoogle Scholar
  6. 6.
    J. R. Willis, J. Mech, Phys. Solids, 25 (1977) 185.CrossRefGoogle Scholar
  7. 7.
    D. P. H. Hasselman, J. Comp. Mat., 12 (1978) 403.CrossRefGoogle Scholar
  8. 8.
    H. Fricke, PUys. Rev., 24 (1924) 575.CrossRefGoogle Scholar
  9. 9.
    A. E. Powers, KAPL-2145, March 1961.Google Scholar
  10. 10.
    J. Selsing, J. Amer. Ceram. Soc., 44 (1961) 419.CrossRefGoogle Scholar
  11. 11.
    B. E. Gatewood, Thermal Stresses, McGraw Hill (1957).Google Scholar
  12. 12.
    J. P. Singh, D. P. H. Hasselman, W. M. Su, J. A. Rubin and R. Palicka, J. Mat. Sc. (in press).Google Scholar
  13. 13.
    A. G. Evans, Acta Met. 26 (1978) 1845.CrossRefGoogle Scholar
  14. 14.
    H. J. Siebeneck, D. P. H. Hasselman, J. J. Cleveland and R. C. Bradt, J. Amer. Ceram. Soc., 59 (1976) 241.CrossRefGoogle Scholar
  15. 15.
    H. J. Siebeneck, D. P. H. Hasselman, J. J. Cleveland and R. C. Bradt, J. Amer. Ceram. Soc., 60 (1977) 336.CrossRefGoogle Scholar
  16. 16.
    Bob R. Powell, Jr., G. E. Youngblook, D. P. H. Hasselman and Larry D. Bentsen, J. Am. Ceram. Soc., 63 (1981) 581.CrossRefGoogle Scholar
  17. 17.
    W. J. Parker, R. J. Jenkins, C. P.Butler and G. L. Abbott, J. Appl. Phys., 32 (1961) 1679 ).Google Scholar
  18. 18.
    D. A. G. Bruggeman, Ann. Physik, 25 (1935) 636.CrossRefGoogle Scholar

Copyright information

© Purdue Research Foundation 1983

Authors and Affiliations

  • D. P. H. Hasselman
    • 1
  1. 1.Department of Materials EngineeringVirginia Polytechnic Institute and State UniversityBlacksburgUSA

Personalised recommendations