Porous composites of aluminum titanate and mixed strontium/calcium feldspar are used as a material in diesel particulate filter applications because of their low thermal expansion, high thermal shock resistance, high heat capacity, high chemical resistance to ash and their ability to be formed into porous materials with porosity >50% with pore sizes that allow efficient filtering of particulate matter within a wide size range without creating an undesirably high backpressure. In the present work, reaction-templated growth of aluminum titanate is explored, where during its high temperature formation aluminum titanate conserves the template morphology and develops texture. The growth of aluminum titanate from simple oxide starting materials is constrained by a number of thermodynamic, kinetic, crystallographic and morphological factors. We have investigated the impact of template shape and crystallographic orientation in single crystalline and polycrystalline reacting mixtures on the material microstructure, its crystallographic texture and the resulting material porosity and thermo-mechanical properties. Reaction-templating is used to derive materials that cover a wide range of porosity, pore size and shape and, in specific cases, also demonstrate enhanced strength.
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