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Nucleation of alpha alumina in boehmite gel

Published online by Cambridge University Press:  31 January 2011

Ladislav Pach ,
Rustum Roy  and
Sridhar Komarneni
Ladislav Pach
Affiliation:
Materials Research Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802
Rustum Roy
Affiliation:
Materials Research Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802
Sridhar Komarneni
Affiliation:
Materials Research Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802
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Abstract

Transformation of boehmitc-derived alumina gel to α–Al2O3 in unseeded gels is strongly influenced by the parent phase, θ-Al2O3. In seeded gels the perfect structure of the epitaxial substrate (α–Al2O3, 0.3 wt. %) influences the surrounding defect θ-phase resulting in (a) fewer imperfections due to lower transformation enthalpy to α–Al2O3, and (b) multiple nucleation sites of α–Al2O3 at the α–Al2O3 seed surface. The rate of transformation expressed for the same number of α–Al2O3 nuclei in unseeded and seeded gels indicates that it is faster in the unseeded gel than in the seeded gel.

Type
Articles
Information
Journal of Materials Research , Volume 5 , Issue 2 , February 1990 , pp. 278 - 285
Copyright
Copyright © Materials Research Society 1990

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References

REFERENCES

1Roy, R., Suwa, Y., and Komarneni, S., in Science of Ceramic Chemical Processing, edited by Hench, L. L. and Ulrich, D. R. (John Wiley, New York, 1986), Chap. 27, pp. 247–258.Google Scholar
2Clark, D. E. and Lannutti, J. J., in Ultrastructure Processing of Ceramics, Glasses and Composites, edited by Hench, L. L. and Ulrich, D. R. (John Wiley, New York, 1984), Chap. 10, pp. 126–141.Google Scholar
3Yoldas, B. E., Ceram. Bull. 54 (3), 289 (1975).Google Scholar
4Wilson, S. J., Proc. Brit. Ceram. Soc. 28, 281 (1979).Google Scholar
5Yamaguchi, G., Yasui, I., and Chiu, W., Bull. Chem. Soc. Jpn. 43 (8), 2487 (1970).Google Scholar
6Wilson, S. J. and Stacey, N. H., J. Colloid Interface Sci. 82 (2), 507 (1981).Google Scholar
7Wilson, S. J. and McConnell, J. D. C., J. Solid State Chem. 34, 315 (1980).Google Scholar
8Messing, G. L., Kumagai, M., Shelleman, R. A., and McArdle, J. L., in Science of Ceramic Chemical Processing, edited by Hench, L. L. and Ulrich, D.R. (John Wiley, New York, 1986), Chap. 28, pp. 259–271.Google Scholar
9Dynys, F.W. and Halloran, J.W., J. Am. Ceram. Soc. 65 (9), 442 (1982).Google Scholar
10Kumagai, M. and Messing, G. L., J. Am. Ceram. Soc. 67 (11), C230 (1984).Google Scholar
11Dynys, F.W. and Halloran, J.W., in Ultrastructure Processing of Ceramics, Glasses and Composites, edited by Hench, L. L. and Ulrich, D. R. (John Wiley, New York, 1984), Chap. 11, pp. 142–151.Google Scholar
12Suwa, Y., Komarneni, S., and Roy, R., J. Mater. Sci. Lett. 5, 21 (1986).CrossRefGoogle Scholar
13Shelleman, R.A., Messing, G.L., and Kumagai, M., J. Non-Cryst. Solids 82, 277 (1986).Google Scholar
14Yarbrough, W. and Roy, R., J. Mater. Res. 2 (4), 494 (1987).Google Scholar
15McArdle, J. L. and Messing, G. L., Adv. Ceram. Mater. 3 (4), 387 (1988).CrossRefGoogle Scholar
16Uhlmann, D.R., Weinberg, M. C., and Teowee, G., J. Non-Cryst. Solids 100, 154 (1988).Google Scholar
17Porter, D. A. and Easterling, K. E., Phase Transformation in Metals and Alloys (VNR, U.K., 1980), pp. 155, 265, and 271.Google Scholar
18Zarzycki, J., in Science of Ceramic Chemical Processing, edited by Hench, L. L. and Ulrich, D. R. (John Wiley, New York, 1986), Chap. 2, p. 21.Google Scholar
19Lange, F. F. and Kellett, B., in Science of Ceramic Chemical Processing, edited by Hench, L. L. and Ulrich, D. R. (John Wiley, New York, 1986), Chap. 59, p. 501.Google Scholar
20Yokokawa, T. and Kleppa, O. J., J. Phys. Chem. 68, 3246 (1964).Google Scholar
21Stull, D. R. and Prophet, H., JANAF Thermochemical Tables, 2nd ed., NSRDS-NBS, 37 (1971).Google Scholar