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Superdendrites in Directional Solidification of Polymer-Solvent Mixtures

Published online by Cambridge University Press:  10 February 2011

Rolf Ragnarsson
Affiliation:
Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853–2501
Brian Utter
Affiliation:
Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853–2501
Eberhard Bodenschatz
Affiliation:
Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853–2501
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Abstract

The directional solidification of the transparent binary alloy succinonitrile-poly(ethylene oxide) was studied in an experiment in which solidification speeds of about 2 mm/sec could be reached without loss of the linear temperature gradient. The low diffusivity of the polymer solute allowed the study of the dynamics of rapid solidification using an optical microscope. For both normal and doublonic dendrites we observed a transition to large triangular “superdendrites” above a certain solidification speed and we report measurements of the primary and secondary spacing as a function of the pulling speed. Our measurements suggest that the observed triangular shape is due to a decoupling of primary and secondary growth at large undercooling.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

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References

REFERENCES

[1] Materials Science and Technology: A Comprehensive Treatment, edited by Cahn, R., Haasen, P., and Kramer, E. (VCH, Weinheim, 1991), Vol.15: Processing of Metalls and Alloys.Google Scholar
[2] Bassler, B., Brunner, R., Hofmeister, W., and Bayuzick, R., Review of Scientific Instruments 68, 1846 (1997).Google Scholar
[3] Wu, Y., Piccone, T. J., Shiohara, Y., and Flemings, M. C., Metallurgical Transactions A 18A, 915 (1987).Google Scholar
[4] For reviews see Billia, B. and Trivedi, R. in Handbook of Crystal Growth, edited by Hurle, D.T.J. (Elsevier, Amsterdam, 1993, Vol.1, Ch. 14. or H. Mueller-Krumbhaar and W. Kurz in Materials Science and Technology: A Comprehensive Treatment, edited by Cahn, R.W. and Haasen, P. and Kramer, E.J. (VCH, Weinheim 1991) Vol. 5, Chap. 10.Google Scholar
[5] Smith, P. and Pennings, J., Journal of Polymer Science 15, 521 (1977).Google Scholar
[6] Smith, P. and Pennings, A. J., Journal of Materials Science 11, 1450 (1976).Google Scholar
[7] Hunt, J., Jackson, K., and Brown, H., Rev. Sci. Instrum. 37, 805 (1966).Google Scholar
[8] We used rectangular glass capillaries manufactured by VitroCom, Inc. The capillaries had the internal dimensions 50 μm by 1 mm, 50 μm walls, and lengths up to 30 cm. They were flame-sealed after filling.Google Scholar
[9] PEO with a polydispersity (normalized molecular weight distribution) of 1.05–1.1 was purchased from Polymer Labs, Inc.Google Scholar
[10] Glicksman, M. E., Schaefer, R. J., and Ayers, J. D., Metallurgical Transactions A 7A, 1747 (1976).Google Scholar
[11] Somboonsuk, K., Mason, J. T., and Trivedi, R., Metall. Trans. A 15A, 967 (1984).Google Scholar
[12] Fainstein-Pedraza, D. and Bolling, G., Journal of Crystal Growth 28, 311 (1975).Google Scholar
[13] Brener, E., Muller-Krumbhaar, H., and Temkin, D., Physical Review E 54, 2714 (1996).Google Scholar