Low sintering temperature cordierite batch and cordierite ceramic produced therefrom

Abstract

The invention is directed at sintered ceramic articles exhibiting a primary crystalline phase of cordierite and an analytical oxide composition, in weight percent, of 44-53% SiO2, 30-38 Al2O3, 11-16% MgO and 0.05 to 10% of a metal oxide. The ceramic article exhibits a coefficient of thermal expansion in at least one direction no greater than about 15.0×10−7° C. over the temperature range of about 25° C. to about 800° C. The sum of the weight percentages of residual mullite, corundum, and spinel, as measured by X-ray diffractometry of the crushed and powdered body, is not greater than 15%. Furthermore, the invention discloses a method of producing the aforementioned ceramic body, comprising (a) selecting a raw material batch mixture for forming the cordierite ceramic body, comprising two or more compounds which serve as an alumina source, a silica source and a magnesia source, and at least one metal oxide source in an amount to result in the cordierite body comprising, on an analytical oxide basis, in weight percent, between about 0.05-10% of the metal oxide; (b) adding an organic binder system to the inorganic mixture and forming the mixture into a green body; (c) drying the green body and thereafter firing the green body at a time and at a temperature no greater than about 1300° C. to result in sintered ceramic body. Preferred metal oxide sources include the oxides or oxide-forming compounds of the metals selected from the group consisting of molybdenum, tungsten, bismuth, copper, yttrium, lanthanide metals and boron.

Dependencies are inferred from the claim text.