Patent ID: 6254822
Filing Date: 2001-07-03
Classification: C04B

Abstract:
A method for producing a sintered ceramic substrate having mullite as its primary phase, comprising the following steps:preparing a plasticizable inorganic raw material mixture having a chemical composition comprising, in percent by weight, of 30 to 60% SiO.sub.2, 30 to 70%, Al.sub.2 O.sub.3, and 1 to 10% MgO, the raw material mixture comprising an amount of pre-reacted mullite powder, an amount of a water-swelling clay and an amount of alumina and/or alumina-yielding precursor;adding an organic binder system to the inorganic mixture;kneading the inorganic mixture;extruding inorganic mixture to form a green substrate; and thereafter,firing the substrate for a time and at temperature sufficient to form a sintered mullite having an acid/base exposure strength loss of less than about 20%.