Regenerator Matrix Materials Based on Ceramic Composites
Research on a large number of inexpensive ceramic composites for regenerator applications is reported. The composites are prepared by hot-pressing and consist of ceramic powders of spin-frustrated spinels in halide matrices, and thermal data on six composites selected to date are given. This series of composites offers specific heats equivalent to, or superior than, those of Er3Ni below 13 K, and thermal diffusivities are about an order of magnitude larger than that of Er3Ni. The composites are tough materials and have indentation-hardness values 10–20 times larger than that of Pb. Future plans are discussed, including the fabrication of composite spheres for user testing.
KeywordsThermal Diffusivity Ceramic Composite Thermal Conductivity Measurement Regenerator Material Knoop Hardness
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- 1.G. Walker, Cryocoolers ( Plenum Press, New York, 1984 ), p. 33.Google Scholar
- 3.H. Nakashima, K. Ishibashi, and Y. Ishizaki, Proc. ICEC 10, Butterworths, Guildford, UK (1984), 54–57.Google Scholar
- 4.M. Sahashi, Y. Tokai, T. Kuriyama, H. Nakagome, R. Li, M. Ogawa, and T. Hashimoto, Adv. in Cryogenic Eng., Vol. 35 ( Plenum Press, New York, 1990, Edit. R. W. Fast ), p. 1175.Google Scholar
- 5.R. Li, O. Yoshida, T. Hashimoto, T. Kuriyama, and H. Nakagome ibid., p. 1183.Google Scholar
- 7.G. Green, J. Chafe, and J. Stevens, ibid., p. 1003.Google Scholar
- 8.R. A. Ackerman, ibid., p. 982.Google Scholar
- 10.W. N. Lawless, C. F. Clark, and T. K. Gupta, Adv. in Cryogenic Eng., Vol. 30 (Plenum, New York, Edit. A. F. Clark and R. P. Reed,1984), p. 433. T. K. Gupta, W. N. Lawless, C. E. Oberly, G. J. Bich, G. R. Wagner, and D. S. Holmes, Adv. in Cryogenic Eng., Vol. 32 ( Plenum, New York, Edit. R. P. Reed and A. F. Clark, 1986 ), p. 225.Google Scholar
- 12.W. N. Lawless, Phys. Rev. B30 6057 (1984) and U. S. Patent Nos. 4,296,147, 4,354,355, and 4, 356, 235.Google Scholar