| 摘要 |
A body is provided of which is made up of at least about 93% by weight cordierite, having a coefficient of thermal expansion of no greater than about 4 x 10<-><7> <o>C<-><1>, from about 25<o>C to about 800<o>C, and a total porosity of greater than about 42%. A method is provided for producing the body which comprises selecting raw materials to form a composition which forms cordierite on firing, the raw materials being composed of: talc having a BET surface area of no greater than about 5 m<2>/g, 0 to about 48% by weight of clay, which can be platelet clay, stacked clay which can be delaminated into platelets during processing, and mixtures thereof, an aluminum oxide yielding component having an average particle size of either about 3 to about 8 micrometers in diameter, or no greater than about 3 micrometers in diameter, and free silica, intimately blending the raw materials with an effective amount of vehicle and forming aids to impart plastic formability and green strength to the raw materials and to form a plastic mixture therefrom. If the particle size of the aluminum oxide yielding component is no greater than about 3 micrometers in diameter, the raw materials are blended additionally with a burnout agent. The raw materials are formed into a green body which is dried and fired at a sufficient temperature for a sufficient time to form the cordierite body. <IMAGE> |
