Preparation of Fine, Spherical, Composite Powder by Spray Pyrolysis
Spray pyrolysis (SP) is an advanced method which enables spherical powder to be prepared through the pyrolysis or hydrolysis reaction of the atomized droplet containing the precursor.1–3 To date most reactor systems have been designed such that the thermolysis and sintering processes overlap. Overlap of these processes in a single droplet could significantly affect densification of the particles. Therefore, a special separate reactor has been recently used in JFCC, see Fig.1, to obtain maximum control of the evaporation, thermolysis and sintering processes and because of this the time temperature conditions are significantly different. Most of the studies4–6 emphasized the compositional flexibility for synthesizing ceramic powders but there have been few attempts to understand or model the processes and factors that affect the production of particles with controlled size and morphology. Recent achievements in the field of the synthesis of powder by powder processing have shown that chemical and physical properties of ceramic materials are highly dependent on the morphology and chemical composition of the starting powder.7,8 Therefore, various properties of ceramic materials are expected to improve by controlling the morphology and composition of the starting powder.
KeywordsComposite Particle Hollow Sphere Spray Pyrolysis Composite Powder Atomize Droplet
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- 3.T. Fukui, T. Obuchi, Y. Ikuhara, S. Ohara, and K. Kodera J. Am. Ceram. Soc. ibid. 80, 261 (1997).Google Scholar
- 5.T.P. O’Holleran, R.R. Neorogaonkar, D.M. Roy and R. Roy, Am. Ceram. Soc. Bull. 57, 459(1978).Google Scholar
- 6.O. Sakurai, M. Miyauchi, N. Mizutani, and M. Kato, J. Ceram. Soc. Jpn. 92, 398 (1989).Google Scholar
- 8.T.H. Estell and S.N. Flengas, J. Electroanal. Chem. ibid. 118, 1890 (1971).Google Scholar
- 9.D.W. Sproson and G.L. Messing, in Ceramic Powder Science, edited by G.L. Messing, K.S. Mazdiyasni, J. W. McCauley, and R. A. Haber, American Ceramic Society, Westerville, OH, 1987.Google Scholar
- 10.K.H. Leong, J. Aerosol Sci. 18, 527 (1987).Google Scholar
- 11.R. Marie et. al., in Proc. Processing and Properties of Advanced Engineering Materials, edited by T. Kobayashi, M. Umemoto, M. Morinaga, ISAEM-97, Toyohashi, 1997, p. 319.Google Scholar
- 12.R. Marie, T. Fukui, S. Ohara, and T. Inagaki to be published in Elec. Solid-State Lett.Google Scholar