Characterization and Sintering Behavior of Alkoxide-Derived Aluminosilicate Powders |
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| Authors: | Yoshihiro Hirata Kazuyoshi Sakeda Yumi Matsushita Kinji Shimada Yoshimi Ishihara |
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| Affiliation: | Department of Applied Chemistry, Faculty of Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890, Japan |
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| Abstract: | Submicrometer SiO2-Al2O3 powders with compositions of 46.5 to 76.6 wt% Al2O3 were prepared by hydrolysis of mixed alkoxides. Phase change, mullite composition, and particle size of powders with heating were analyzed by DTA, XRD, IR, BET, and TEM. As-produced amorphous powders partially transformed to mullite and Al-Si spinel at around 980°C. The compositions of mullite produced at 1400° and 1550°C were richer in Al2O3 than the compositions of stable mullite solid solutions predicted from the phase diagram of the SiO2-Al2O3 system. Particle size decreased with increasing Al2O3 content. The sintered densities depended upon the amount of SiO2-rich glassy phase formed during sintering and the green density expressed as a function of particle size. |
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| Keywords: | mullite sintering powders alkoxide silica |
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