Advertisement

International Journal of Thermophysics

, Volume 17, Issue 5, pp 1025–1036 | Cite as

Thermophysical properties of thoriated tungsten above 3600 K by a pulse-heating method

  • F. Righini
  • J. Spišiak
  • G. C. Bussolino
  • A. Rosso
  • G. K. White
Article

Abstract

Thoriated tungsten (tungsten, 98% thorium oxide, 2%) is a widely used electrode material for inert-gas arc-welding. A subsecond pulse-heating technique was applied to rod specimens: radiance temperature was measured by high-speed pyrometry. Literature values of the temperature dependence of the normal spectral emissivity of tungsten were used to obtain true temperatures, with the melting point of thoriated tungsten as a calibration point. Experimental results obtained in the temperature range from 3600 K to the melting point (3693 K) are presented and discussed, along with data obtained during the initial part of the free cooling period. The electrical resistivity results show a regular behavior up to the melting point, indicating that thoria remains an insulator up to 3680 K. During heating, a heat capacity anomaly is found near 3666 K, interpreted as the melting point of thoria. During cooling, two anomalies are found, the first one with a peak near 3660 K and a second one (possibly a Frenkel disorder) with a peak near 3148 K.

Key words

electrical resistivity Frenkel disorder heat capacity melting point thoria tungsten welding electrodes 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    F. Righini, A. Rosso, and G. Ruffino,High Temp. High Press. 4:597 (1972).Google Scholar
  2. 2.
    F. Righini, A. Rosso, and L. Coslovi, inProceedings of the Seventh Symposium on Thermophysical Properties. A. Cezairliyan, ed. (ASME, New York, 1977), pp. 358–368Google Scholar
  3. 3.
    F. Righini and A. Rosso,Measurement 1:79 (1983).Google Scholar
  4. 4.
    F. Righini, J. Spišiak, G. C. Bussolino, A. Rosso, and J. HaidarInt. J. Thermophys. 15:1311 (1994).Google Scholar
  5. 5.
    L. Coslovi, F. Righini, and A. Rosso,Alta Frequenza 44:592 (1975).Google Scholar
  6. 6.
    F. Righini, G. C. Bussolino, and A. Rosso, in Temperature. Its Measurement and Control in Science and Industry, Vol. 6, J. F. Schooley, ed., (American Institute of Physics. New York, 1992), pp. 763–768.Google Scholar
  7. 7.
    C. Horrigan, J. Haidar, and F. Righini,Int. J. Thermophys. 17:1037 (1996).Google Scholar
  8. 8.
    J. C. DeVos,Physica 20:690 (1954).Google Scholar
  9. 9.
    L. N. Latyev, V. Ya. Chekhovskoi, and E. N. Shestakov,High Temp. High Press. 4:679 (1972).Google Scholar
  10. 10.
    A. P. Müller and A. Cezairliyan,Int. J. Thermophys. 11:619 (1990).Google Scholar
  11. 11.
    F. Righini, J. Spišiak, G. C. Bussolino, and A. Rosso,High Temp. High Press. 25:193 (1993).Google Scholar
  12. 12.
    F. Righini, J. Spišiak, G. C. Bussolino, and A. Rosso, inProceedings Tempmeko '93 (Tech-Market, Prague, 1993), pp. 360–366.Google Scholar
  13. 13.
    A. Cezairliyan,High Temp. Sci. 4:248 (1972).Google Scholar
  14. 14.
    F. Righini, G. C. Bussolino, A. Rosso, and J. Spišiak,Int. J. Thermophys. 14:485 (1993).Google Scholar
  15. 15.
    H. Preston-Thomas,Metrologia 27:3 (1990).Google Scholar
  16. 16.
    T. G. Kollie, D. L. McElroy, and C. R. Brooks, Oak Ridge National Laboratory Report ORNL-TM-2517 (1969).Google Scholar
  17. 17.
    W. A. Lamberston, M. H. Mueller, and F. H. Gunzel Jr.,J. Am. Ceram. Soc. 36:397 (1953).Google Scholar
  18. 18.
    R. Benz,J. Nucl. Mat. 29:43 (1969).Google Scholar
  19. 19.
    F. Sibeude and C. Bonet, inColloques Internationaux CNRS No. 205 (CNRS, Paris, 1972), pp. 53–56.Google Scholar
  20. 20.
    M. H. Rand, inI. Thermomechanical Properties in Thorium: Physico-Chemical Properties of its Compounds and Alloys, Atomic Energy Review, Special Issue No. 5, O. Kubaschewski, ed. (IAEA, Vienna, 1975).Google Scholar
  21. 21.
    M. Bober, H. U. Karov, and K. Müller,High Temp. High Press. 12:161 (1930).Google Scholar
  22. 22.
    W. Hayes (ed).Crystals with the Fluorite Structure (Oxford Press, Oxford, 1974).Google Scholar
  23. 23.
    W. Hayes,J. Phys. Colloque C6 41:C6 (1980).Google Scholar
  24. 24.
    J. Hiernaut. G. J. Hyland, and C. Ronchi,Int. J. Thermophys. 14:259 (1993).Google Scholar
  25. 25.
    M. T. Hutchings, K. Clausen, W. Haves, J. E. McDonald, R. Osborn, and P. Schnabel,High Temp. Sci. 20:97 (1995).Google Scholar
  26. 26.
    M. T. Hutchings,J. Chem Soc., Faraday Trans. 83:1083 (1937).Google Scholar
  27. 27.
    D. F. Fischer, J. K. Fink, and L. Leibowitz.J. Nucl. Mater. 102:220 (1981).Google Scholar
  28. 28.
    J. Belle and R. M. Berman, inThermal Conductivity 18, T. Ashworth and D. R. Smith, eds. (Plenum Press. New York. 1934), pp,. 483–494. [See. also by the same authors, Report WARD-TM-1530 (1982)]Google Scholar

Copyright information

© Plenum Publishing Corporation 1996

Authors and Affiliations

  • F. Righini
    • 1
  • J. Spišiak
    • 2
  • G. C. Bussolino
    • 1
  • A. Rosso
    • 1
  • G. K. White
    • 3
  1. 1.CNR Istituto di Metrologia “G. Colonnetti,”TorinoItaly
  2. 2.Institute of PhysicsSlovak Academy of SciencesBratislavaSlovakia
  3. 3.CSIRO Division of Applied PhysicsLindfieldAustralia

Personalised recommendations