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Nucleation mechanisms in chemically vapor-deposited mullite coatings on SiC

Published online by Cambridge University Press:  31 January 2011

Ping Hou ,
S. N. Basu  and
V. K. Sarin
Ping Hou
Affiliation:
Department of Manufacturing Engineering, Boston University, 15 St. Mary's Street, Boston, Massachusetts 02215
S. N. Basu*
Affiliation:
Department of Manufacturing Engineering, Boston University, 15 St. Mary's Street, Boston, Massachusetts 02215
V. K. Sarin
Affiliation:
Department of Manufacturing Engineering, Boston University, 15 St. Mary's Street, Boston, Massachusetts 02215
*
a) Address all correspondence to this author. e-mail: basu@bu.edu
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Abstract

Dense, uniform, and adherent chemically vapor-deposited mullite coatings were deposited on SiC substrates using the AlCl3–SiCl4–H2–CO2 system. Typical coating morphology consisted of a thin interfacial layer of γ–Al2O3 nanocrystallites embedded within a vitreous SiO2-based matrix. When a critical Al/Si ratio of 3.2 ± 0.29 was reached within this nanocrystalline layer, mullite crystals nucleated and grew as columnar grains. The thickness of the nanocrystalline layer decreased as the input AlCl3/SiCl4 ratio was increased. In all cases, the Al/Si composition in the coating increased from the coating/substrate interface to the coating surface. Critical factors leading to the nucleation and growth of mullite crystals are discussed in this article.

Type
Articles
Information
Journal of Materials Research , Volume 14 , Issue 7 , July 1999 , pp. 2952 - 2958
Copyright
Copyright © Materials Research Society 1999

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References

REFERENCES

1.Schneider, H., Okada, K., and Pask, J.A., Mullite and Mullite Ceramics (John Wiley & Sons Ltd., Chichester, 1994).Google Scholar
2.Mulpuri, R.P. and Sarin, V.K., J. Mater. Res. 11, 1315 (1996).CrossRefGoogle Scholar
3.Sarin, V.K. and Mulpuri, R., U.S. Patent No. 5 763 008 (1998).Google Scholar
4. Powder Diffraction Files, International Center for Diffraction Data, Swathmore, PA, (1991).Google Scholar
5.Nakajima, Y., Morimoto, N., and Wanatabe, E., Proc. Japan. Acad. 51, 173 (1975).CrossRefGoogle Scholar
6.Doppalapudi, D. and Basu, S.N., Mat. Sci. Eng. A231, 48 (1997).CrossRefGoogle Scholar
7.Cameron, W.E., Am. Mineral. 62, 747 (1977).Google Scholar
8.Komarneni, S. and Roy, R., J. Am. Ceram. Soc. 68(9), C–243 (1985).Google Scholar
9.Komarneni, S. and Roy, R., J. Am. Ceram. Soc. 69(3), C–42 (1985).Google Scholar
10.Yokoyama, T., Nishu, K., Torii, S., and Ikeda, Y., J. Mater. Res. 12, 2111 (1997).CrossRefGoogle Scholar
11.Yoldas, B.E. in Ceramic Transactions, Vol. 6, Mullite and Mullite Matrix Composites, edited by Sōmiya, S., Davis, R.F., and Pask, J.A.. (American Ceramic Society, Westerville, OH, 1990), p. 255.Google Scholar