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Directionally Solidified Mullite Fibers

Published online by Cambridge University Press:  15 February 2011

Ali Sayir  and
Serene C. Farmer
Ali Sayir
Affiliation:
NASA Lewis Research Center, Cleveland, Ohio 44135Case Western Reserve University
Serene C. Farmer
Affiliation:
NASA Lewis Research Center, Cleveland, Ohio 44135
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Abstract

Directionally solidified fibers with nominal mullite compositions of 3Al2O3·2SiO2 were grown by the laser heated float zone (LHFZ) method at NASA Lewis. High resolution digital images from an optical microscope evidence the formation of a liquid-liquid miscibility gap during crystal growth. Experimental evidence shows that the formation of mullite in aluminosilicate melts is in fact preceded by liquid immiscibility. The average fiber tensile strength is 1.15 GPa at room temperature. The mullite fibers retained 80 % of their room temperature tensile strength at 1450 °C. SEM analysis revealed that the fibers were strongly faceted and that the facets act as critical flaws. Examined in TEM, these mullite single crystals are free of dislocations, low angle boundaries and voids. Single crystal mullite showed a high degree of oxygen vacancy ordering. Regardless of the starting composition, the degree of order observed in polycrystalline fibers was lower than that observed in the mullite single crystals.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 365: Symposium M – Ceramic Matrix Composites–Advanced High-Temperature Structural Materials , 1994 , 11
Copyright
Copyright © Materials Research Society 1995

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References

1. Becher, P. F., J. Am. Ceram. Soc., 74 [2] 255 (1991).Google Scholar
2. Dixon, R. D., Chevacharoenkul, S., Davis, R. F. and Tiegs, T. N., in Ceramic Transactions edited by Somiya, S.. Davis, R. F., and Pask, J. A. (Am Ceram Soc., Westerville, OH, 1990) pp.579–603.Google Scholar
3. Al-Assafi, S., Cruse, T., Simmons, J. H., Brennan, A. B., and Sacks, M. D. (unpublished work).Google Scholar
4. Aksay, I. A., Dabbs, D. M., and Sarikaya, M., J. Am. Ceram. Soc., 74 [10] 2343 (1991).Google Scholar
5. Dokko, P. C., Pask, J. A., and Masdiyasni, K. S., J. Am. Ceram. Soc., 60 [3-4] 150 (1977).Google Scholar
6. Mah, T. and Masdiyasni, K. S., J. Am. Ceram. Soc., 66 [10] 699 (1983).Google Scholar
7. Okamoto, Y., Fukudome, H., Hayashi, K., and Nishikawa, T., J. Europ. Ceram. Soc., 6, 161 (1990).Google Scholar
8. Liu, H. Y., Weisskopf, K. L., Hoffmann, M. J. and Petzow, G., J. Europ. Ceram. Soc., 123 (1989).Google Scholar
9. Bowen, N. L. and Greig, J. W., J. Am. Ceram. Soc., 7 [4] 238 (1924).Google Scholar
10. Holm, J. L. and Kleppa, O. J., Am. Mineral., 51 [11-12] 1608 (1966).Google Scholar
11. Cameron, W. E., Am. Mineral., 62 [111] 747 (1977).Google Scholar
12. Bauer, W. H., Gordon, I. and Moore, C. H., J. Am. Ceram. Soc., 33 [4] 140 (1950).Google Scholar
13. Aramaki, S. and Roy, R., J. Am. Ceram. Soc., 45 [5] 229 (1962).Google Scholar
14. Aksay, I. A. and Pask, J. A., Science, 183 [4120] 69 (1974)Google Scholar
15. Aksay, I. A. and Pask, J. A., J. Am. Ceram. Soc., 58 [12] 507 (1975).Google Scholar
16. Klug, F. J., Prochazka, S. and Doremus, R. H., J. Am. Ceram. Soc., 70 [10] 750 (1987).Google Scholar
17. Pask, J. A., in Ceramic Transactions, edited by Somiya, S.. Davis, R. F.. and Pask, J. A. (Am Ceram Soc., Westerville, OH, 1990) pp. 1–13.Google Scholar
18. Roy, R., in Ceramic Transactions, edited by Somiya, S.. Davis, R. F.. and Pask, J. A. (Am Ceram Soc., Westerville, OH, 1990) pp.45–50.Google Scholar
19. Rishbud, S. H., in Ceramic Transactions, edited by Somiya, S.. Davis, R. F.. and Pask, J. A. (Am Ceram Soc., Westerville, OH, 1990) pp.61–71.Google Scholar
20. Kriven, W. M. and Pask, J. A., J. Am. Ceram. Soc., 66 [9] 649 (1983).Google Scholar
21. Roy, R., and Francis, E. E., Am. Mineral., [7] 725 (1953).Google Scholar
22. Kanzaki, S., Tabata, H., Kumazawa, T., and Ohta, S., J. Am. Ceram. Soc., 68 [1] C6 (1985).Google Scholar
23. Ismail, M. G. M. U., Nakai, Z., and Somiya, S., J. Am. Ceram. Soc., 70 [1] C7 (1987).Google Scholar
24. Sayir, A., Hurst, J. B., and Jones, S., in Proc. of the 2nd Ann. HITEMP Rev. (1989), NASA Conference Publication 10039.Google Scholar
25. Humphreys, L. B., Heminger, J. A., and Young, G. W., J. Cryst. Growth, [100] 31 (1990).Google Scholar
26. Brown, R. A., AICHE Journal, 34 [6] 881 (1988).Google Scholar
27. Feigelson, R. S., MRS Bull., [10] 47 (1988).Google Scholar
28. Kim, K. M., J. Appl. Phys., 50 [2] 1135 (1979).Google Scholar
29. Saifi, M., Dubois, B., Vogel, E. M., and Thiel, F. A., J. Mat. Res., 1 [3] 452 (1986).Google Scholar
30. Kim, K. M., Dreben, A. B., and Schujko, A., J. Appl. Phys., 50 [6] 4472 (1979).Google Scholar
31. Aramaki, S. and Roy, R., J. Am. Ceram. Soc., 43 [8] 670 (1960).Google Scholar
32. Glasser, F. P., Warshaw, I., and Roy, R., Phy. Chem. Glasses, 1, 39 (1960).Google Scholar
33. Rishbud, S. H. and Pask, J. A., J. Am. Ceram. Soc., 60 [6] 418 (1977).Google Scholar
34. Bolling, G. F. and Tiller, W. A., J. Appl. Phys., 31, 1345 (1960).Google Scholar
35. Boiling, G. F. and Tiller, W. A., J. Appl. Phys., 31, 2040 (1960).Google Scholar
36. Anisimov, Y. S., Grits, E. F. and Mitin, B. S., Inorganic Mat, 13 [8] 1444 (1977).Google Scholar
37. Galakhov, F. Y. and Konovalova, S. F., Bull. Acad. Sci. USSR Div. Chem. Sci. 8 1373 (1964)Google Scholar
38. McDowell, J. F. and Beall, G. H., J. Am. Ceram. Soc., 52, 17 (1969).Google Scholar
39. Kuo, C. K., in Ceramic Transactions, edited by Somiya, S.. Davis, R. F.. and Pask, J. A. (Am Ceram Soc., Westerville, OH, 1990) pp.51–58.Google Scholar