Texturing of mullite by templated grain growth with aluminum borate whiskers

Textured mullite was produced by templated grain growth with a mixture of m ullite powder and aluminum borate (9Al(2)O(3). 2B(2)O(3)) whiskers. A gated doctor blade was used to align the whiskers in the c-axis in the mullite m atrix during tape casting. When heated by themselves in air, aluminum borat e whiskers formed chi -Al2O3 at > 1400 degreesC but were stable enough for templated mullite growth in a TiO2-doped mullite sintered at 1500 degreesC. Starting with 3 wt.% TiO2, and 10 wt % templates, an similar to 90% textur ed mullite was obtained after 6 h at 1600 degreesC. The < 001 > textured mu llite was 97% dense and had a FWHM of 9.6 in the [001]. (C) 2001 Elsevier S cience Ltd. All rights reserved.