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Microwave Processing of Metalorganics to Form Powders, Compacts, and Functional Gradient Materials

Published online by Cambridge University Press:  29 November 2013

Monika A. Willert-Porada
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Microwave heating offers the unique potential for selectively heating a strongly microwave-absorbing material within a nonabsorbing matrix, providing the mixture is homogeneous and the absorbing phase is diluted enough to retain a penetration depth sufficient for volumetric heating. Mainly for this reason, microwave processing opens up a way to produce entirely new materials and microstructures that cannot be processed by conventional methods. By proper selection of raw materials and microwave heating conditions, processes can be tailored to produce desired materials and structures, such as powders, compacts, or functional gradient materials, as described in this article.

Synthetic powders with controlled morphology, agglomerate structure, and composition are necessary to improve the reliability of ceramic materials. A novel approach to synthesizing such powders is based on microwave heating of metalorganic precursor compounds. In contrast to conventional precursor-based methods for powder syntheses, which use diluted solutions of precursor compounds, the main objective of microwave processing is to develop a method for direct pyrolysis of the precursor compound into a ceramic powder, produced by simultaneous decomposition of the precursor within the whole volume of the reaction mixture. Besides a simple pyrolysis of a single precursor compound, decomposition of precursor mixtures is also possible, eventually followed by further reaction of the components. Furthermore, an inert or reactive powdery matrix-material can be impregnated with the precursor and then converted to an “alloyed” ceramic powder.

A new method for microstructural modeling of ceramic materials combines precursor compounds with heating by microwave radiation to introduce a second phase and to control grain growth.

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Type
Microwave Processing of Materials
Information
MRS Bulletin , Volume 18 , Issue 11 , November 1993 , pp. 51 - 57
Copyright
Copyright © Materials Research Society 1993

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References

1.Willert-Porada, M., Krummel, T., Rohde, B., and Moormann, D., in Microwave Processing of Materials III, edited by Beatty, R.L., Sutton, W.H., and Iskander, M.E. (Mater. Res. Soc. Symp. Proc. 269, Pittsburgh, PA, 1992) p. 199.Google Scholar
2.Brinker, C.J. and Scherrer, G., in Sol-Gel Science, the Physics and Chemistry of Sol-Gel Processing (Academic Press, New York, 1989).Google Scholar
3.Willert-Porada, M., in Microwave Processing of Materials III, in Reference 1, p. 193.Google Scholar
4.Miamoto, Y., Ceram. Bull. 69 (1990) p. 686.Google Scholar
5.Willert-Porada, M., Gerdes, T., and Vodegel, S., in Microwave Processing of Materials III, in Reference 1, p. 205.Google Scholar
6.Sproson, D.W., Messing, G.L., and Gardner, T.J., Ceram. Int. 12 (1986) p. 3.CrossRefGoogle Scholar
7.Lanutti, J.J., Schilling, C., and Aksay, I.A., in Processing Science of Advanced Ceramics, edited by Aksay, I.A., McVay, G.L., and Ulrich, D.R. (Mater. Res. Soc. Symp. Proc. 155, Pittsburgh, PA, 1989) p. 155.Google Scholar
8.Caughlan, C.N., Katz, W., and Hodgson, W.J., J. Am. Chem. Soc. 73 (1951) p. 5654.Google Scholar
9.Schmidt, F., Master's thesis, University of Dortmund, 1990.Google Scholar
10. Data from CRC Handbook of Chemistry and Physics (CRC Press, 61st Edition, 1981).Google Scholar
11.Cotton, F.A., in Progress in Inorganic Chemistry, Vol. II (1960) p. 336.Google Scholar
12.Willert-Porada, M., “Reaction Rate Controlled Microwave Processing of Ceramic Materials,” in Microwaves: Theory and Application in Materials Processing II, edited by Clark, D.E., Laia, J.R., and Tinga, W.R. (Am. Ceram. Soc., Ceram. Trans. 36, Westerville, OH, October 1993) (in press).Google Scholar
13.Willert-Porada, M., Krummel, T., Rohde, B., and Gerdes, T., German Patent Application No. P 42 13 832.9 (April 28, 1992); German Patent Application No. P 42 14 631.3 (April 24, 1992).Google Scholar
14.Willert-Porada, M., unpublished data.Google Scholar
15.Gerdes, T. and Willert-Porada, M., presented at the 1992 DGM Annual Meeting, Hamburg, 1992 (unpublished).Google Scholar
16.Borchert, R., Master's thesis, University of Dortmund, 1993.Google Scholar
17.Willert-Porada, M., Gerdes, T., and Fischer, B., “Application of Microwaves to Combustion Processing of Al2O3-TiC Ceramics,” in Reference 12.Google Scholar
18.Fischer, B., Master's thesis, University of Dortmund, 1992.Google Scholar
19.Willert-Porada, M., Schmidt, F., and Schaarwachter, W., DKG Proc. (Nümberg, 1990) p. 2.Google Scholar
20.Marpl, B.R. and Grun, D.J., J. Am. Ceram. Soc. 72 (1989) p. 2043.CrossRefGoogle Scholar
21.Willert-Porada, M. and Vodegel, S., in Microwaves: Theory and Application in Material Processing (Am. Ceram. Soc., Ceram. Trans. 21, Westerville, OH, 1991) p. 631.Google Scholar
22.Willert-Porada, M., Gerdes, T., Goldbach, T., and Schmidt, F., DKG Proc. (Bayreuth, October 1992) p. 127 and p. 212.Google Scholar
23.Gerdes, T., Master's thesis, University of Dortmund, 1991.Google Scholar
24.Vodegel, S., Hannappel, C., and Willert-Porada, M., presented at the 1993 DGM Annual Meeting, Friedrichsfeld, Germany, 1993 (unpublished).Google Scholar
25.Billing, E.M., Master's thesis, University of Dortmund, 1992.Google Scholar
26.Paksocimas, C.A., Varela, J.A., Longo, E., and Whittemore, O.J., Solid State Phenomena 25–26 (1992) p. 285.CrossRefGoogle Scholar
27.Izumi, K., J. Am. Ceram. Soc. 72 (1989) p. 1465.CrossRefGoogle Scholar
28.Willert-Porada, M. and Vodegel, S., German Patent Application No. P 42 24 974.0 (July 29, 1992).Google Scholar