Abstract: A method of manufacturing a ceramic body and a gas sensor is disclosed. The method comprises mixing a ceramic material and an organometallic material with a solvent to form a mixture. The organometallic material comprises both a metallic component and an organic ligand. The mixture is disposed onto a surface, dried, and removed to form the ceramic body. The sensor is made by disposing the ceramic body adjacent to an unfired electrolyte body having an electrode disposed on each side thereof to form a green sensor. The green sensor is co-fired to form the sensor.

Abstract: A method of fabricating a discontinuous-fiber, ceramic matrix green-state composite component. The method includes preparation of a mixture of discontinuous fibers, in a quantity equal to about 100% of a desired end-product fiber quantity thereof, and a polymer-derived ceramic precursor resin in an excess quantity greater than about 150% of a desired end-product resin quantity thereof. The mixture so prepared then is introduced into a cavity of a molding tool and a vacuum is applied to the cavity through a vacuum aperture leading from the cavity. The mixture is drawn toward the vacuum aperture and consequently compacts a quantity of fibers within the cavity at the aperture site such that the fibers function as a filter to efficiently retain within the cavity fibers within the original mixture while removing under vacuum the excess resin that provided an effective vehicle for carrying and dispersing the discontinuous fibers.

Abstract: A suspension adhesive comprised of a matrix material and a particulate filler material is useful for bonding, sealing, repairing, and modifying ceramic, glass, and powdered metal components in a light source. A method for making the suspension adhesive includes the selection of a filler material and a volume percentage of the filler material. Additionally, a matrix material is selected and the filler material is dispersed throughout the matrix material. The suspension adhesive is used to bond and seal components to form, for example, an arc tube for a light source.

Abstract: A low-cost, efficient method of preparing hierarchically ordered structures by combining, concurrently or sequentially, micromolding, latex templating, and cooperative self-assembly of hydrolyzed inorganic species and amphiphilic block copolymers.

Abstract: The disclosure describes a method to fabricate nanostructures by integrating the steps of attriting precursor nanometer-sized particulate materials, desorbing the exposed surfaces of the attrited nanoparticulates, adsorbing a surfactant on at least 50% of the desorbed surfaces and dispersing the surfactant-coated nanoparticulates in an organic matrix to form a homogeneous thermoplastic compound from which green nanostructures are shaped, dewaxed and sintered. The method substantially overcomes the problems of aggregation, contamination and pyrophoricity inherent in nanoparticulates.

Abstract: Disclosed is a method for producing an SiC preform of a high volume fraction used for the manufacture of a metal matrix composite. The method involves the steps of mixing SiC particles of different particle sizes each selected from a range of 0.2 to 48 &mgr;m with an organic binder, an inorganic binder, an aggregating agent, and distilled water, thereby producing a mixture, and stirring the mixture in accordance with a ball milling process, thereby producing a slurry containing the SiC particles, pouring the slurry containing the SiC particles into a mold having upper and lower molds respectively provided with absorbent bodies, and squeezing the slurry in the mold, thereby reducing a residual moisture content of the slurry, completely drying the slurry reduced in residual moisture content, thereby producing an SiC preform, and calcinating the SiC preform. The preform is impregnated with a metal matrix while maintaining a high reinforcement volume fraction of 70 vol % or more.

Abstract: The invention relates to a method for producing a solid molded article, in particular a ceramic and/or metallic article made of pulverized particles. The invention also relates to stable dispersions of pulverized particles in an aqueous fluid medium, solid molded articles made of pulverized particles, and sintered ceramic and/or metallic molded articles.

Abstract: A health support device having a lamination of a semiconductor film on a surface of a partially-reduced sintered material of titanium oxide. The semiconductor film is preferably a p-type semiconductor film of silicon or germanium. The partially-reduced sintered material is preferably represented by TiO2−x, where 0<×<0.5. The thickness of the semiconductor film is preferably from 1 nm to 500 nm. In production, a mixture of a titanium oxide powder and a binder is press-molded, and the molded material is sintered at a temperature of from 500° C. to 1100° C. in a vacuum, inert or reducing atmosphere. A p-type semiconductor film is formed on a surface of the resulting partially-reduced sintered material of titanium oxide.

Abstract: The disclosure describes a method to fabricate nanostructures containing isotropically distributed, interconnected pores having cross-sectional diameters in the nanometer and Angstrom range by integrating the steps of attriting precursor nanometer-sized particulate materials, desorbing the exposed surfaces of the attrited nanoparticulates, adsorbing a surfactant on 25-50% of the desorbed surfaces and dispersing the surfactant-coated nanoparticulates in an organic matrix to form a homogeneous thermoplastic compound from which green nanostructures are formed, dewaxed and sintered to the desired degree of microporosity.

Abstract: A procedure is provided for bringing an incompletely densified cast radome to a desired final or near final shape through the use of one or more conformal tools during a high temperature firing operation. A conformal firing tool is defined in this case as a mandrel or mold made from a high temperature material, such as a graphite composite, that represents the desired shape of the finished radome. The process consists of firing the cast radome body over a mandrel, or inside a mold, or in combination with the two, such that the tools impart a desired dimensionality to the cast part as it densities and flows at high temperature.

Abstract: Semiconductor wire bonding tools used in the assembly and interconnection of integrated circuits (ICs) are micromolded from a mixture of ultrafine particulate materials mixed with an organic binder. Following extraction of the binder the green bonding tools are sintered during which they undergo isotropic, constant and accurately predetermined shrinkage. Hence semiconductor wire bonding tools can be produced with virtually no limit to miniaturization, thus allowing the fabrication of higher integrated semiconductor products.

Abstract: A continuous process for the manufacture of a ceramic sintered compact wherein the process comprises the steps of: forming a green compact from a powder mixture comprising a first component comprising compounds which contain elements of silicon, aluminum, oxygen and nitrogen; and the powder mixture further comprising a second component comprising a compound of at least one element selected from the group consisting of yttrium, scandium, cerium, lanthanum and the metals of the lanthanide series, and the second component comprising between 0.1 and 10 weight percent of the powder mixture; heat treating the green compact wherein the heat treatment comprises continuously passing the green compact through at least one heating zone so as to produce a sintered compact.

Abstract: Methods for consolidation and densification of multi-phase composite structures are provided. These methods allow for more efficient and less expensive consolidation and densification of two- and three-dimensional multi-phase components having more complex geometries.

Abstract: A method to produce polycrystalline sapphire or ruby watch jewels is disclosed. Green watch jewels are formed from a mixture of fine ceramic powders with a thermoplastic binder. Following extraction of the binder the parts are sintered to net shape and full density. The method obviates the inefficient and labor intensive technique of monocrystalline watch jewel manufacturing. The purity of the raw materials and processing conditions result in sintered polycrystalline rubies or sapphires with homogeneous microstructures, small grain size and hardness similar to that of their synthetic monocrystalline counterparts.

Abstract: A method of manufacturing a ceramic body and a gas sensor is disclosed. The method comprises mixing a ceramic material and an organometallic material with a solvent to form a mixture. The organometallic material comprises both a metallic component and an organic ligand. The mixture is disposed onto a surface, dried, and removed to form the ceramic body. The sensor is made by disposing the ceramic body adjacent to an unfired electrolyte body having an electrode disposed on each side thereof to form a green sensor. The green sensor is co-fired to form the sensor.

Abstract: The dielectric constant of low loss tangent glass-ceramic compositions, such as cordierite-based glass ceramics, is modified over a range by selective addition of high dielectric constant ceramics, such as titanates, tantalates and carbides and metals, such as copper. The low loss tangent is retained or improved over a range of frequencies, and the low CTE of the glass-ceramic is maintained. BaTiO3, SrTiO3 and Ta2O5 produce the most effective results.

Abstract: Provided is an aluminum nitride sintered body excellent in thermal shock resistance and strength and applicable to a radiating substrate for a power module or a jig for semiconductor equipment employed under a strict heat cycle. An aluminum nitride sintered body obtained with a sintering aid of a rare earth element and an alkaline earth metal element contains 0.01 to 5 percent by weight of an alkaline earth metal element compound in terms of an oxide and 0.01 to 10 percent by weight of a rare earth element compound in terms of an oxide, and the amount of carbon remaining in the sintered body is controlled to 0.005 to 0.1 percent by weight, thereby suppressing grain growth and improving thermal shock resistance and strength of the sintered body.

Abstract: An improved submerged entry nozzle is provided which is useful in the casting of aluminum killed molten steel. The nozzle has an improved slagline sleeve or collar which surrounds the outer portion of the nozzle to protect it from corrosion during the casting process. The slagline sleeve is made from resin bonded zirconia/graphite which has been formulated so that upon curing of the resin to form resite, there is a reduction in the contractile tendency which results in a reduction in stress fracturing. The reduction of the contractile tendency and the resulting resistance to stress fracturing is achieved by adding an effective amount of calcium oxide to the resin-zirconia-graphite mixture which is used to form the sleeve.

Abstract: A composition for production of silica glass using a sol-gel process is described, comprising silica particles, a dispersing agent, and a solution containing a polymerizable monomer for formation of acrylic resin and a crosslink agent dissolved in distilled water. The polymerizable monomer is n-methylol acrylamide or n-methylol methacrylamide. A method for production of silica glass is described, including the step of adding silica particles and a dispersing agent to a premix solution of the polymerizable monomer for formation of acrylic resin and the crosslink agent dissolved in distilled water.

Abstract: A method for producing a powder-molded body is provided, including the steps of casting a slurry containing a powder of at least one of a ceramic and a metal, and organic dispersion medium, and a gelling agent into a mold, and solidifying the slurry by gelling the slurry to obtain a molded body. The slurry is solidified by chemically bonding an organic dispersion medium having reactive functional groups and a gelling agent. The method is capable of improving gelling (solidification) efficiency and obtaining a molded body having a high density, a small firing shrinkage, and high shape precision, and which hardly experiences cracks during drying and firing.

Abstract: Exemplary silicon carbide ceramic bodies having inclusions therein are produced according to the invention. An exemplary ceramic body includes silicon carbide in major amounts and unreacted particles of an additive in minor amounts which are bonded to the matrix. The particles are dispersed throughout the silicon carbide, and are preferably selected from one or more of the group consisting of boron nitride, aluminum nitride and titanium diboride.

Abstract: Provided are a method for producing ceramic green sheets used for making a ceramic substrate which is reduced in cracking failure and improved in adhesion between laminated layers and is high in lamination property, high in strength and excellent in surface roughness, said method including heat-treating the ceramic powder having a specific particle size by dry grinding a ceramic powder to prepare ceramic powder having a specific average degree of aggregation and preparing a slurry using the ceramic powder so that a green density of the resulting ceramic green sheets is in a desired range, and a method for making a ceramic laminated substrate having excellent various properties by laminating the above ceramic green sheets and firing the laminate.

Abstract: A method of removing substantially all of the volatile component in a green, volatile-containing ceramic article is disclosed. The method comprises freezing the ceramic article; and then subjecting the frozen article to a vacuum for a sufficient time to freeze-dry the article. Frequently, the article is heated while being freeze-dried. Use of this method efficiently reduces the propensity for any warpage of the article. The article is often formed from a ceramic slurry in a gel-casting process. A method for fabricating a ceramic core used in investment casting is also described.

Abstract: A method for producing a powder-molded body,includes: casting a slurry containing a powder of a ceramic and/or a metal, a dispersion medium, and a gelling agent; and solidifying the slurry by gelling the slurry to obtain a molded body. The slurry is solidified by chemically bonding an organic dispersion medium having reactive functional groups and a gelling agent. The method is capable of improving gelling (solidification) efficiency and obtaining a molded body with a high density, a small firing shrinkage, and a high shape precision while scarcely causing cracks at the time of drying and firing.

Abstract: The invention utilizes green support structures during sintering to maintain the shape, reduce sagging and prevent separate part sections from coming into contact and fusing together during the sintering process. In the most preferred embodiment, monolithic green structures are form with integrated support green structures that are released from the parts after sintering. Preferably monolithic green structures are formed by the Mold Shape Deposition Manufacturing (Mold SDM) process. By the method described, complex sintered structures can be made having interlocking and independently movable interlocking parts.

Abstract: A plasticizable raw material batch mixture for forming a silicon carbide honeycomb structure comprising the following components: (1) powdered silicon metal; (2) a carbon precursor comprising a water soluble crosslinking thermoset resin having a viscosity of less than about 1000 centipoise (cp), and preferably less than about 500 cp; (3) a powdered silicon-containing filler; and, (4) a water soluble thermoplastic binder. Optionally, the batch mixture can include either, or both, an organic fibrous filler and a pore-forming filler comprising either a graphitic or a thermoplastic pore-forming filler.

Abstract: A method of firing a green cordierite-ceramic honeycomb structural body containing a carbonaceous material, for example, an organic binder, comprising a two phase process. The first phase comprises firing the green honeycomb structural body in a firing atmosphere to a temperature and for a time sufficient to initiate and sufficiently achieve release of the carbonaceous material while introducing into the firing atmosphere a fluorine-free low-oxygen gas comprising less than about 20% O2, by volume. Once the carbonaceous material is sufficiently released, the second phase involves conventionally firing the green body for a time and a temperature sufficient to initiate and sufficiently achieve the conversion of the green ceramic honeycomb structural body into a fired honeycomb body.

Abstract: A method for manufacturing the roller carrier of a vibration balance device, the roller carrier is installed with at least one round track around a rotary axis thereof for carrying a plurality of rollers; characterized in that: the roller carrier is made of ceramic powder and made by a process of ceramic powder metallurgy. The material of the powder is A92A aluminum oxide or zirconium oxide, or other proper metal oxide. The manufacturing process of the ceramic powder metallurgy includes the steps of: feeding material, compacting, sintering, and polishing, or other manufacturing process of the ceramic powder metallurgy can be used, which includes the steps of feeding material, pelletizing, injection molding, debinding, sintering, and polishing. The roller carrier from aforementioned processes uses less materials, can be mass-produced, has a precise dimension, is light weighted, has a smooth surface and has a high surface hardness.

Abstract: There is provided a process for obtaining a cordierite honeycomb structural body with thin cell walls and no molding defects such as cell breakage or the like. Cell breakage is prevented by limiting the maximum particle size of the cordierite starting material powder to no greater than 85% of the slit width of the extrusion molding die so that the starting material particles will not clog inside the slits or the introduction port of the slits. As one cordierite starting material, talc with a mean particle size of 5 &mgr;m or greater is used to give a honeycomb structural body with a void volume of greater than 30%, for production of a honeycomb structural body, with good moldability, having a small thickness and a low heat capacity. It is preferred to add to the starting material at least a lubricant/humectant, a binder and/or a mixture of a water-soluble polyhydric alcohol derivative and a polyhydric alcohol.

Abstract: The invention concerns binders for ceramic materials, in particular water soluble sugars and sugar alcohols.

Abstract: The present invention relates to a molding composition based on sinterable materials, comprising

Abstract: A binder system for use in the formation of ceramic or other powder-formed greenware including a binder, a solvent for the binder, a surfactant, and a component that is non-solvent with respect to the binder and solvent. The non-solvent component exhibits a lower viscosity than the solvent when containing the binder and includes a low molecular weight oil having a 90% recovered distillation temperature range of between about 220 to 400° C. Also disclosed is a process of forming and shaping plasticized powder mixtures and a process for forming ceramic articles utilizing the binder system.

Abstract: A gelcasting composition has improved drying behavior, machinability and shelf life in the dried and unfired state. The composition includes an inorganic powder, solvent, monomer system soluble in the solvent, an initiator system for polymerizing the monomer system, and a plasticizer soluble in the solvent. Dispersants and other processing aides to control slurry properties can be added. The plasticizer imparts an ability to dry thick section parts, to store samples in the dried state without cracking under conditions of varying relative humidity, and to machine dry gelcast parts without cracking or chipping. A method of making gelcast parts is also disclosed.

Abstract: A method and composition for combining ceramic powder and binder to form green elements suitable for shaping and firing uses dry blending techniques. The binder includes a particulate wax component that is not melted in order to combine it with the ceramic powder, but rather, the wax component is combined in particulate form with the ceramic powder. The particulate wax is mixed in conventional blender apparatus in a relatively short time period. The binder composition may also include a lubricity enhancer or slip agent and a dispersion or colloidal binder.

Abstract: A fired body and method for producing the body that involves compounding the components of powder materials, binder, aqueous solvent for the binder, and non-solvent with respect to at least the solvent, binder, and powder materials. The non-solvent is made up of a high molecular weight organic portion having a molecular weight of greater than 200, and a low molecular weight organic portion having a molecular weight of up to 200. The components are mixed and plasticized to form a plasticized mixture which is then shaped to form a green body. The green body is then dried and fired.

Abstract: A fossil molding fabrication method includes the steps of (1) preparing a fossil skeleton material; (2) mixing the fossil skeleton material with water to form a paste-like fossil skeleton material, then filling the paste-like fossil skeleton material in the cavity of a flexible mold; (3) preparing a base rock material, then mixing the base rock material with water to form a paste-like base rock material, and then covering the paste-like base rock material over the fossil skeleton in the flexible mold; and (4) keeping the paste-like base rock material away from the radiation of the sun and letting it be dried in the air, and then removing the molding thus formed from the mold, so as to obtain a fossil molding. A cover rock may be covered on the base rock over the fossil skeleton.

Abstract: The invention concerns a process for manufacturing a part made of high temperature-resistant, ceramic material based on aluminum nitride and reaction sintering. The process comprises the steps of preparing a homogeneous mixture of boron nitride powder, aluminum powder and a paste-like binder, capable of solidifying by chemical reaction and by solvent loss through drying. The mixture is formed by mold casting and then pressed and heated, to a temperature not exceeding approximately 70° C., to harden the binder and to obtain a solid and manipulable unfired part. The binder is eliminated by heating to a temperature of approximately 300° C. Pores of the unfired part are impregnated by immersing the part in a bath of molten aluminum or aluminum alloy to form an impregnated preform. Thereafter, the impregnated preform is removed from the bath, cooled, and machined to the final dimensions of the part. A ceramic is obtained by reaction sintering the machined part at a temperature of 900 to 1000° C.

Abstract: A method for forming an article involves forming a mixture of components of powder materials, organic binder, solvent for the binder, non-solvent with respect to at least the binder, the solvent, and the powder materials, wherein the non-solvent is lower in viscosity than the binder combined with the solvent, and an agent for retarding the oxidation of the organic components. The components are mixed and plasticized, and shaped into a green structure which is then fired to impart strength and form the product article. The product article has fewer cracks than it would have absent the oxidation-retarding agent.

Abstract: A process for increasing the particles size of fines of a titaniferous mineral containing more that 45% by weight of titanium. The process comprises mixing the fines with a binding agent and water to produce an agglomerate. The agglomerate is then dried and sintered.

Abstract: A binder system for use in the formation of ceramic or other powder-formed greenware which includes a binder, a solvent for the binder, a surfactant, and a component that is non-solvent with respect to the binder and solvent. The non-solvent component exhibits a lower viscosity than the solvent when containing the binder and includes at least a portion of an organic liquid having a 90% recovered distillation temperature of no greater than about 225.degree. C. and more preferably less than 220.degree. C. Also disclosed is a process of forming and shaping plasticized powder mixtures and a process for forming ceramic articles utilizing the binder system.

Abstract: The present invention relates to a method for ore pelletization including the step of adding binder polymer to particulate ore and moisture to form an intimate mixture. Green pellets are formed from the mixture and fired. A water soluble treatment polymer having a molecular weight of 1,000 to 20,000 is included in the intimate mixture in an amount of at least 0.001% by weight. The water soluble treatment polymer is formed by polymerization of water soluble ethylenically unsaturated monomer blend containing at least 50% by weight of anionic monomer.

Abstract: A method for forming and shaping powder mixtures involves compounding, homogenizing, and plasticizing components to form a mixture. The components are powder materials, binder, solvent for the binder, surfactant, and non-solvent with respect to at least the binder, the solvent, and the powder materials. The non-solvent is lower in viscosity than the binder combined with the solvent. The components are chosen to result in improved wet green strength in the subsequently formed green body. The compounding is done by the steps of dry-mixing the powder material, surfactant and binder to form a uniform blend, adding the solvent to the resulting dry blend, and thereafter adding the non-solvent to the blend. The mixture is shaped by passing it through a low to moderate shear extruder, and then through a die to form a green body. The compounding and shaping steps are carried out at a temperature of no greater than ambient temperature. The method is especially suitable for RAM extrusion.

Abstract: A method of firing a green cordierite-ceramic honeycomb structural body containing a carbonaceous material, for example, an organic binder, comprising a two phase process. The first phase comprises firing the green honeycomb structural body in a firing atmosphere to a temperature and for a time sufficient to initiate and sufficiently achieve release of the carbonaceous material while introducing into the firing atmosphere a fluorine-free low-oxygen gas comprising less than about 20% O.sub.2, by volume. Once the carbonaceous material is sufficiently released, the second phase involves conventionally firing the green body for a time and a temperature sufficient to initiate and sufficiently achieve the conversion of the green ceramic honeycomb structural body into a fired honeycomb body.

Abstract: A radome is fabricated by mixing a mass of ceramic powders, a dispersant chemical, a prepolymer material, and a solvent together to form a casting mixture, which is then cast into a mold having the shape of a radome. The prepolymer material in the casting mixture is cured, and the casting mixture is dried. The molded article is heated to a burnout temperature sufficiently high to vaporize the prepolymer material and the dispersant chemical, and thereafter the molded article is heated to a sintering temperature sufficiently high to sinter the ceramic particles.

Abstract: Powder mixtures and a method of forming and shaping the mixtures. The method involves compounding the components of powder materials, binder, solvent for the binder, surfactant, and non-solvent with respect to at least the binder, the solvent, and the powder materials. The non-solvent is lower in viscosity than the binder combined with the solvent. The solvent is present in an amount that is less than the amount that would be present otherwise. The components are mixed and plasticized, and shaped to form a green body. The choice of components results in improved wet green strength in the green body. The method is especially useful for extrusion processing of aqueous binder systems such as water and cellulose ethers and hydrophobic non-solvents, to form structures such as honeycombs. In the body, the ratio, upon subsequent firing, of the isostatic strength to the A-axis strength is at least about 20% higher than in bodies made without the mixture composition of the invention.

Abstract: A method for making ink jet print head base elements which includes the steps of making a sacrificial mold of the ink jet print head, binder coagulation casting a ferroelectric, piezoelectric ceramic slurry into the sacrificial mold to form a green ceramic base element, and sintering the green ceramic base element while in the sacrificial mold to thereby burn off the sacrificial mold and yield a sintered, net shape, molded ink jet print head. complex shapes to thereby reduce the numbers of complex manufacturing steps. A three dimensional jet printing process can be used to form the sacrificial molds. Once the sacrificial mold has been made, a ferroelectric material (and preferably a piezoelectric material) is prepared using a binder coagulation process. The slurry of the ferroelectric material, preferably lead zirconium titinate (PbZrTiO.sub.3 hereinafter referred to as PZT) is poured into the mold. Once the ferroelectric material is poured into the mold, a chemical initiator is added.

Abstract: A method of gelcasting includes the steps of providing a solution of at least hydroxymethylacrylamide (HMAM) and water. At least one inorganic powder is added to the mixture. At least one initiator system is provided to polymerize the HMAM. The initiator polymerizes the HMAM and water, to form a firm hydrogel that contains the inorganic powder. One or more comonomers can be polymerized with the HMAM monomer, to alter the final properties of the gelcast material. Additionally, one or more additives can be included in the polymerization mixture, to alter the properties of the gelcast material.

Abstract: A method for forming molded articles in any shape from ceramic, glass, or metal powders which comprises: preparing a slurry by dispersing more than one powder selected from a group consisting of ceramic, glass, and metal materials in a dispersing medium using a dispersing agent, and curing by adding a reactive substance that reacts with the dispersing agent to make the dispersibility of the dispersing agent disappear or lower.

Abstract: The present invention provides a method of preparing semi-wet pressed green bodies having improved wet strength. The wet strength of the semi-wet pressed green bodies is increased by the addition of at least one polymeric binder having a molecular weight greater than 50,000 comprising, as polymerized units, at least 10 percent of one or more monoethylenically unsaturated acids, salts, or anhydrides, and further comprising at least one hydrophobe per polymeric chain on average. The present invention further provides semi-wet pressed green bodies, having improved wet strength, made from the above method.In one embodiment, the polymeric binder increases the wet strength of ceramic green bodies. In another embodiment, the polymeric binder increases the wet strength of metallurgic green bodies. In another embodiment, the polymeric binder increases the wet strength of cermet green bodies.

Abstract: A method of fabricating a cordierite ceramic honeycomb structural body which includes the following steps: formulating a batch of raw materials comprising a mixture of kaolin clay, talc, alumina and other cordierite-forming materials, each included in the batch in an effective amount such that the batch is capable of yielding a fired honeycomb body whose predominant crystal phase is cordierite; 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; forming the raw materials into a green honeycomb structural body by extrusion and thereafter drying and firing the green honeycomb structural body. The firing of the green honeycomb structural body is accomplished through a four-phase heating process as follows (1) heating the green body to a first temperature ranging between about 750-850.degree. C.; (2) heating to a second temperature ranging between about 1250 to 1350.degree.