Abstract
The laser pulse method can be successfully applied to the measurement of thermal diffusivity of isotropic materials subject to some assumptions. For anisotropic materials, this method is applicable to the measurement of principal thermal diffusivity only on the condition that there is no difference in direction between the principal axis and that of the temperature gradient. After analyzing the heat conduction process in an anisotropic solid, it has been shown that large errors in the measurement of thermal diffusivity would exist if the direction of the principal axis deviates inconspicuously from that of the temperature gradient. The experimental results of thermal diffusivity of highly oriented pyrolytic graphite (HOPG) samples with various deviation angles have been compared with the analytical results. The laser pulse method is not applicable to measurements on semitransparent pyrolytic boron nitride (PBN). We adopted a two-layer composite sample to measure the thermal diffusivity of PBN in the c direction and a particular graphite-PBN composite sample has been prepared which has a very low thermal resistance at the interface. The thermal diffusivity and thermal conductivity of PG (below 2300°C) and PBN (below 1000°C) are given.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Y. S. Touloukian, R. W. Powell, C. Y. Ho, and P. G. Klemens, Thermophysical Properties of Matter, Vol. 2, Thermal Conductivity, Nonmetallic Solids (Plenum, New York, 1970), pp. 30–41.
M. R. Null, W. W. Lozier, and A. W. Moore, Carbon 10:352 (1972).
S. Nasu, T. Takahashi, and T. Kikuchi, J. Nucl. Mat. 43:72 (1972).
J. E. Parrott and A. D. Stuckes, Thermal Conductivity of Solids (Pion, London, 1975), pp. 127–128.
X. Z. Zhang, The Method to Measure Thermal Diffusivity of Anisotropic Materials by Laser Pulse Technique, M.S. thesis (IMR, Academia Sinica, Shenyang, 1983) (Chinese).
A. Simpson and A. D. Stuckess, J. Phys. C Solid State Phys. 4:1710 (1971).
R. F. Bulmer and R. Taylor, High Temp. High Press. 6:491 (1974).
J. F. Nye, Physical Properties of Crystals (Oxford University Press, London, 1957), p. 195.
W. J. Parker, R. J. Jenkins, C. P. Butler, and G. L. Abbott, J. Appl. Phys. 32:1679 (1961).
G. H. He, Q. H. Ye, Z. Q. Di, and B. L. Zhou, J. Eng. Therm. 2:283 (1981) (Chinese).
G. H. He, Q. H. Ye, S. Q. Dong, Z. Q. Di, and B. L. Zhou, Acta Metrol. Sin. 4:168 (1983) (English).
R. D. Cowan, J. Appl. Phys. 34:926 (1963).
P. W. Zhang, Z. H. Li, R. Z. Chang, X. N. Zhou, and L. B. Lou, J. Eng. Therm. 3:413 (1982) (Chinese).
X. Z. Zhang, G. H. He, Z. Wei, and B. L. Zhou, Private communication (1985).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
He, G.H., Zhang, X.Z., Wei, Z. et al. Suggestions regarding thermal diffusivity measurements on pyrolytic graphite and pyrolytic boron nitride by the laser pulse method. Int J Thermophys 7, 789–802 (1986). https://doi.org/10.1007/BF00503836
Issue Date:
DOI: https://doi.org/10.1007/BF00503836