Preparation of Mullite Whiskers from AIF(3), SiO(2), and A1(2)O(3) Powders.
Patent Application, Filed 8 Feb 89,
DEPARTMENT OF THE NAVY WASHINGTON DC
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This patent application discloses a process for preparing mullite whiskers by 1 forming an anhydrous, intimate, uniform mixture of Aluminum Fluoride, Aluminum Oxide and Fused Silicon Dioxide powders in an amount selected to produce stoichiometric mullite or a solid solution of Al2O3 in stoichiometric mullite 2 heating the mixture in anhydrous Silicon Tetrafluoride atmosphere at a temperature of from about 700 C to about 950 C to form barlike topaz crystals 3 heating the barlike topaz in an anhydrous SiF4 atmosphere at a temperature of from about 1150 C to about 1700 C to produce the mullite whiskers. Keywords Ceramic fibers. kt
- Ceramics, Refractories and Glass