Accession Number : ADD014530

Title :   Preparation of Mullite Whiskers from AIF(3), SiO(2), and A1(2)O(3) Powders.

Descriptive Note : Patent Application, Filed 8 Feb 89,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Talmy, Inna G ; Haught, Deborah A

Report Date : 08 Feb 1989

Pagination or Media Count : 20

Abstract : 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)

Descriptors :   *WHISKER COMPOSITES, *WHISKERS(CRYSTALS), *PATENT APPLICATIONS, ALUMINUM, ALUMINUM OXIDES, ATMOSPHERES, CERAMIC FIBERS, FLUORIDES, MIXTURES, SILICON

Subject Categories : Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE