Sintering of oxides

Y. Murata and R. Smoak in S. Somiya and S. Saito, eds., Proc. Int. Sjmp. of Factors in Densification and Sintering of Oxide and Nonoxide Ceramics, Gakujutsu Biinken Fukyu-Kai, Tokyo, 1979, p. 382. 

Y. Murata and R. H. Smoak, Proceedings of the International Symposium on Pactors in Densification Sintering of Oxide Non-Oxide Ceramics, Hakone, Japan, 1979 pp. 382-399. 

T Shimohira, A Makishima, K Kotani, M Wakakuwa. In S Somiya, S Saito, eds. Proc Int Symp Factors in Densification and Sintering of Oxide and Non-Oxide Ceramics. Tokyo Tokyo Institute of Technology, 1978, pp 119-127. 

The conventional methods of mullite preparation are the following crystallization from melt, high-temperature sintering of oxides, high-temperature annealing of kaolin [32]. Mechanical activation of hydrated oxides brings to decrease of mullite synthesis temperature [32-39]. 

This is a purely empirical relationship based on Tammann s discovery in 1932 (ref. 78) that there was a minimum temperature at which a solid would undergo a solid-solid interaction. Since that time other workers reported that the rates of sintering of oxides increased markedly at about half the value of the absolute melting temperature. It was also found that under these circumstances defects in the surface of a solid became mobile enabling the surface migration of ions to take place. It should be realized that the Tammann temperature does not represent a discontinuity of behavior, but rather a temperature in the vicinity of which a rapid change in the rate of motion of ions or atoms occurs. 

The heating of the fiber up to 1000 - 1200 °C decreased the value of specific surface because of sintering of oxide particles. The fibrous alumina-based materials annealed above 1400 °C become more sintered, their porosity did not exceed 30 %, the specific surface decreased down to 5 m2/g, and the grain sizes were 100-150 nm. At the same time, the strength of this material was enhanced. 

Kingery WD, Niki E, Narasimhan MD (1961) Sintering of oxide and carbide-meal compositions in presene of a liquid phase. J Am Ceram Setc 44 29-35... 

Johnson, D. L., Impurity effects in the initial stage sintering of oxides, in Sintering and Related Phenomena, G. C. Kucz5mski, N. A. Hooton and C. F. Gibbon (eds), Gordon and Breach, New York, 393-400, 1967. 

Finally, the calcined gel is sintered to achieve a high density and to stabilize the microstructure. The sintering of oxides produced by the sol-gel route can be performed at much lower temperatures than necessary for classical powders, owing to their extremely fine grain size. This is one of the key features of sol-gel processed ceramics. 

Shimohira T., Makishima A., Kotani K., Wakakuwa M. Sintering of monodispersed amorphous silica particles. Proceedings of the International Symposium on Factors in Densification and Sintering of Oxide and Non-oxide Ceramics, October 3-5, 1978, Hakone, Japan Smith J.P., Messing G.L. Sintering of bimodaUy distributed alumina powders. J. Am. Ceram. Soc. 1984 67 238-242... 

Densification Kinetics During Nonisothermal Sintering of Oxides ... 

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