Skip to main content Accessibility help
×
Home

Microstructural Evaluation of Sintered Nanoscale Sic Powders Prepared by various Processing Routes

  • W. R. Schmidt (a1), G. McCarthy (a1), B. Palosz (a2), S. Stel'makh (a2), M. Aloshina (a2), S. Gierlotka (a2), P. Zinn (a3), D. G. Keil (a4) and H. F. Calcote (a4)...

Abstract

Microstructural analysis was performed on several crystalline SiC samples previously prepared by three separate processing methods and subsequently sintered under high pressure and high temperature conditions using the cubic anvil cell MAX80 at Hasylab. Microcrystalline SiC was prepared using SHS conditions, while nanocrystalline SiC was prepared using both combustion synthesis methods and polymer precursors. High purity, highly disordered nanocrystalline SiC powders, with average particle diameters below 100 nm, were synthesized via combustion methods from precise mixtures of silane and acetylene. The properties of the silicon carbide powders prepared in this manner were dependent on the initial stoichiometry and pressure of the combustion mixture. Pyrolysis of polymer precursors to SiC was also used to fabricate ceramic powders containing uniformly-sized, highly disordered nanocrystalline SiC grains. The grain sizes ranged from approximately 3 nm to greater than 50 nm, and depended on the initial composition of the polymer, the pyrolysis conditions, as well as the annealing atmosphere, temperature and time. This paper describes the preparation methods for each of the SiC powders, the densification procedure, and preliminary results obtained primarily from transmission electron microscopy and X-ray diffraction analysis.

Copyright

References

Hide All
1. Palosz, B., Stel'makh, S., Gierlotka, S., Aloszyna, M., Pielaszek, R., Zinn, P., Peun, T., Bismayer, U., and Keil, D. G., “High Pressure Diffraction Studies of Flame-Generated Silicon Carbon Powders”, unpublished work presented at the American Ceramic Society Annual Meeting, Cincinnati, OH, May 1997.
2. Tsurekawa, S., Hasegawa, Y., Sato, K., Sakaguchi, Y., and Yoshinaga, H., "Effect of Crystal Structure on High Temperature Deformation Behaviour of Silicon Carbides", Materials Trans., JIM, 34[8], 675–81 (1993).
3. Nadeau, J. S., "Very High Pressure Hot Pressing of Silicon Carbide", Ceramic Bulletin, 52[2], 170–74 (1973).
4. Yamada, O., Miyamoto, Y., and Koizumi, M., "High Pressure Self-Combustion Sintering of Silicon Carbide", Ceramic Bulletin, 64[2] 319–21 (1985).
5. Yoshida, M., Onodera, A., Ueno, M., Takemura, K., and Shimomura, O., "Pressure-Induced Structure Transition in SiC", Physical Review B, 48[14] 10587–90 (1993).
6. Stel'makh, S., Gierlotka, S., Palosz, B., Mohan, M., Divakar, C., Baumik, S. K., and Singh, A. K., “Effect of High Pressure on Polytypism and Stacking Disorder in Sintered SiC”, XXIII IUCrystallography Congress, Seattle, USA (1996).
7. Siegel, R. W., “Creating Nanophase Materials”, Scientific American, 7479 (December 1996).
8. Maehara, Y. and Langdon, T. G., “Review - Superplasticity in Ceramics”, J. Mater. Sci., 25[5] 2275 (1990).
9. Chen, I.-W. and Xue, L. A., “Development of Superplastic Structural Ceramics”, J. Am, Ceram. Soc., 73[9] 2585 (1990).
10. Wakai, F., Kodama, Y., Sakaguchi, S., Murayama, N., Izaki, K., and Niihara, K., Nature, 344 421423 (March 29, 1990).
11. Keil, D. G., Calcote, H. F. and Gill, R. J., “Flame Synthesis of High Purity, Nanosized Crystalline Silicon Carbide Powder”, in Covalent Ceramics III - Science and Technology of Non-Oxides, edited by Hepp, A. F., Kumta, P. N., Sullivan, J. J., Fischman, G. S., and Kaloyeros, A. E., Mat. Res. Soc. Symp. Proc., 410, 167172 (1996).
12. a) Interrante, L. V., Schmidt, W. R., Marchetti, P. S., and Maciel, G. E., “Pyrolysis of Organometallic Precursors as a Route to Novel Ceramic Materials”, Mat. Res. Soc. Symp. Proc., 249, 3143 (1992); b) L. V. Interrante, W. J. Hurley, Jr., W. R. Schmidt, D. Kwon, R. H. Doremus, P. S. Marchetti, and G. E. Maciel, “Preparation of Nanocrystalline Composites by Pyrolysis of Organometallic Precursors”, in Advanced Composite Materials, Ceramic Transactions Vol.19, American Ceramic Society, Westerville, OH, pp. 3–17 (1991).
13. Pampuch, R., Stobierski, L. and Lis, J., “Synthesis of Sinterable β-SiC Powders by a Solid Combustion Method”, J Am. Ceram. Soc., 72[8] 1434–35 (1989).
14. Palosz, B., Stel'makh, S., and Gierlotka, S., “Refinement of Polycrystalline Disordered Cubic Silicon Carbide by Structure Modeling and X-ray Diffraction Simulation”, Zeitschriftfur Kristallographie, 210, 731–40 (1995).
15. Palosz, B., Stel'makh, S. and Gierlotka, S., “Simulation of Stacking Faults Effect on X-ray Patterns of SiC”, Mat. Sci. Forum, 410, 235–40 (1994).
16. Schmidt, W. R., “Novel Precursor Approaches for CMC Derived by Polymer Pyrolysis” Final Technical Report on AFOSR Contract F49620-91-C-0017 to United Technologies Research Center, February 15, 1994.
17. Schmidt, W. R., “Silicon-Based Nanostructural Ceramics Derived from Polymer Precursors: Development of Processing, Structure & Property Relationships”, Progress Report #3 to AFOSR on Contract No. F49620-95-C-0020 to United Technologies Research Center, August, 1997.

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed