Importance

Loading Importance Indicators...

Abstract

A plasticizable raw material mixture for use in preparing a substrate having cordierite as its primary phase with a mixture of a chemical composition, percent by weight, of 11 to 17% MgO, 33 to 41% Al.sub.2 O.sub.3 and, 46 to 53% SiO.sub.2, the mixture including the following (1) a platy talc having a morphology index of greater than 0.8 and exhibiting a mean particle size of less than about 5 .mu.m; (2) an Al.sub.2 O.sub.3 forming source comprising an alumina having a mean particle size of less than about 5 .mu.m selected from the group consisting of .varies.-alumina, transition aluminas, aluminum oxide monohydroxide, or aluminum trihydrate having; and, (3) one or more of the components of delaminated kaolin having a mean particle size of less than about 2 .mu.m, calcined kaolin exhibiting a mean particle size of less than about 2 .mu.m and a surface area of greater than about 10 m.sup.2 /g and/or silica having a mean particle size of less than about 5 .mu.m., and a method of producing a green body by compounding and plasticizing a cordierite-forming raw material mixture, forming the mixture into a green ceramic body by extrusion through an extrusion die to at least partially align the raw materials in an orientation plane in such a manner that the shrinkage of the green ceramic body upon firing is anisotropic and is greater in direction perpendicular to the orientation plane than in at least one other direction in the green ceramic body.

Loading the Abstract Image...

First Claim