Patent ID: 7628951

Claim:
A process for making a ceramic component comprising: obtaining a slurry comprising a quantity of ceramic powder having a mean particle size from about 1 micron to about 10 microns dispersed in water or a mixture of water and non-aqueous solvents; wherein the ceramic powder is present from about 10%-75% by weight of slurry; the ceramic powder being selected from the group consisting of alumina, alpha-alumina, boehmite, pseudoboehmite, diaspore, bauxite, beta-alumina, theta-alumina, gamma-alumina, and aluminum hydroxide; a quantity of fiber from about 0%-60% by weight of slurry, as a reinforcement phase; a quantity of pore-former, from about 0%-45% by weight of slurry; a quantity of second phase, from about 0%-75% by weight of slurry, wherein the second phase is in the form of fibers or powders selected from the group consisting of carbides, nitrides, borides, silicates, oxides, sulfates, aluminates, mixed oxides, mullite, zirconia, magnesia, spinel, chrome oxide, yttria, carbon, aluminosilicate, kyanite, clay, bentonite, sudaglass, iron oxide, glass frit, titania, perlite, zircon, vermiculite, silica, aluminum, iron, steel, zinc, copper, barium sulfate, zirconium diboride, calcium fluoride, pyrophillite, baddeleyite, magnesium, heat resistant polymeric powders or fibers, and hollow or solid alumina spheres, zirconia spheres, fillite spheres, and silica spheres; a quantity of one or more organic additives selected from a group of organic dispersants, binders, plasticizers, drying aids, molding aids, preservatives, biocides, viscosity thinning aids, or viscosity thickening aids, from about 0% to 25% by weight of slurry; mixing the slurry with a phosphoric acid to produce a slip such that the molar ratio of total aluminum to total phosphorus from the phosphoric acid is between 8 and about 65 and wherein the slip is mixed at a temperature between 15° C. and less than 100° C.; pouring the slip into a mold to form a green component by a process including chemical reaction bonding of the ceramic powder under the influence of said phosphoric acid; and applying a heat treatment to the green component.