Abstract: The present invention relates to a method for producing a porous silicon nitride sintered body having high strength and low thermal conductivity, which comprises of adding more than 10 volume % of rodlike beta-silicon nitride single crystals with a larger mean diameter than that of a silicon nitride raw powder into a mixture comprising the silicon nitride raw powder and a sintering additive, preparing a formed body with rodlike beta-silicon nitride single crystals oriented parallel to the casting plane according to a forming technique such as sheet casting and extrusion forming, sintering said formed body to develop elongated silicon nitride grains from the added rodlike beta-silicon nitride single crystals as nuclei and obtain the sintered body with the elongated grains being dispersed in a complicated state.

Abstract: A moldable ceramic composition is made by forming the suspension of electrically charged ceramic particles and then coagulating.

Abstract: A method of manufacturing a flat, glass-like or ceramic moulding having a structured surface, in which a rotationally symmetrical, moist green body is manufactured from a suspension of a highly dispersed, powdered solid material and a dispersing agent by centrifuging in a hollow mould, whereafter said green body is removed from the hollow mould and, if necessary, rolled out subsequently, cut up and, after which it is spread out on a structure-imparting substrate, the surface is embossed by applying pressure and, subsequently, the glass-like or ceramic moulding is produced by drying and sintering.

Abstract: This invention relates to tape casting a silicon carbide slip to eventually produce a silicon carbide wafer having a thickness of between 0.5 and 1 mm and a diameter of at least 150 mm, the wafer preferably having a strength of at least 30 MPa, and a porosity wherein at least 85% of the pores are no larger than 12 microns.

Abstract: The present invention provides silicon nitride ceramics having high thermal conductivity and a method for production thereof. This invention relates to a method for producing a silicon nitride sintered body having a microstructure with silicon nitride crystals oriented uniaxially and exhibiting high thermal conductivity of 100 to 150 W/mK in the direction parallel to the orientation direction of the crystals, which comprises of preparing a slurry by mixing a mixed powder of a sintering auxiliary, beta-silicon nitride single crystals as seed crystals and a silicon nitride raw powder with a dispersing medium, forming the slurry by tape casting or extrusion forming, calcining the formed silicon nitride body with beta-silicon nitride single crystals oriented parallel to the casting plane to remove the organic components, densifying it by hot pressing and the like if required, and further annealing it at 1700 to 2000.degree. C. under the nitrogen pressure of 1 to 100 atmospheres.

Abstract: The present invention relates to a silicon nitride sintered body having a remarkably increased strain-to-fracture, a low elasticity and high strength, characterized by consisting of a layered structure of alternating porous silicon nitride layers 1 to 1000 .mu.m thick with a porosity of 5 to 70 volume % and dense silicon nitride layers 1 to 1000 .mu.m thick with a porosity of less than 5 volume %, being layered as materials with optional tiers. In addition, this invention relates to a method for producing the silicon nitride sintered body as described above, which comprises of forming dense layers and porous layers by sheet casting or extrusion forming so as to prepare the layers to be capable of 1 to 1000 .mu.m thick after sintering, stacking them to obtain layered materials with optional tiers and sintering them at 1600.degree. to 2100 .degree. C. under a nitrogen atmosphere.

Abstract: Thin inorganic sintered structures having strength and flexibility sufficient to permit bending without breakage in at least one direction to a radius of curvature of less than 20 centimeters, methods for making them, and products incorporating them, are described. Preferred sintered ceramic structures according to the invention can comprise zirconias, titanias, aluminas, silicas, rare earth metal oxides, alkaline oxides, alkaline earth metal oxides and first, second, and third transition series metal oxides and combinations thereof and therebetween. Sintered metal structures can also be provided.

Abstract: A single crystal silicon sheet is formed from a polycrystalline sheet by melting a relatively small portion of the sheet at an initial location and defining a single crystallographic orientation for the silicon by placing a small silicon seed crystal in contact with the melted silicon at the initial location. The melted portion is then moved from the initial location throughout the sheet to move impurities in the sheet to the edges of the sheet and to extend the crystallographic orientation of the silicon established at the initial location to the whole sheet, inwardly of the edges. The edges containing impurities and any remaining polycrystalline structure are removed to produce a sheet of single crystal silicon. A polycrystalline sheet may be formed by spreading a slurry of a silicon powder, a binder, and solvent on a surface and allowing the solvent to evaporate to form a sheet. The sheet is moistened to cause it to expand and sheer clear of the surface.

Abstract: A method for producing ceramic tape used to fabricate electronic devices while eliminating continued shrinkage of the unfired tape. Chemical agents are added to a mixture of ceramic powder and binder to manipulate the crosslinking of the binder. A first approach involves promoting the crosslinking reaction to completion quickly. The second approach involves preventing the crosslinking reaction during the tape slurry mixing and casting processes. A solvent is used to accelerate the crosslinking of the binder in which the solvent may include one or more of acetone, acetylacetone, toluene and ethanol. Preferably, the solvent is a combination of acetone and acetylacetone. A polyhydroxy compound, such as glycerine, may be added to accelerate the crosslinking reaction of the binder. The boron in the tape may alternatively be rendered inoperative as a crossing agent for the binder by pre-reacting the boron with the Lewis base prior to contact with the binder.

Abstract: A ceramic green sheet includes ceramic particles having a spherical diameter of 0.01-0.5 .mu.m of a primary particle as a ceramic component, an average degree of aggregation of 10 or less, wherein the ceramic green sheet contains at most 1 vol % of secondary particles having a diameter of 20 .mu.m or more and has a surface roughness (Ra) of 0.2 .mu.m or less. A method for producing a ceramic substrate having a thickness of 30 .mu.m or less includes the steps of: preparing a ceramic slurry by mixing a ceramic powder with an organic binder and at least one organic solvent, and adjusting a viscosity to be within the range of 100-10,000 mPa's; removing coarse aggregated particles from the ceramic slurry; molding the ceramic slurry into a ceramic green sheet by a reverse roll coater method; and firing the ceramic green sheet so that an average crystal grain size be 2 .mu.m or less.

Abstract: A process for producing a silica sintered product for a multi-layer wiring substrate of the invention includes: providing a fine silica powder having an average particle size of 5 to 500 nm and a fine crystallized quartz powder having an average particle size 1 to 10 .mu.m, the fine crystallized quartz powder having a volume equal to 1 to 20% of the entire volume of the fine silica powder and the fine crystallized quartz powder; mixing the fine silica powder and the fine crystallized quartz powder with a binder and a solvent to form a silica-containing slurry; forming a green sheet by slip-casting the silica-containing slurry; and firing the green sheet at a temperature of 800.degree. to 1200.degree. C. in an atmosphere containing steam at a partial pressure of 0.005 to 0.85 atm.

Abstract: The invention concerns the field of slip casting for producing green compacts. The disadvantage of state-of-the art slip casting is among others the need for removing the water through porous molds, the resulting shrinkage and the tendency of the green compact to form shrinkage cracks. These disadvantages are eliminated by internally coagulating by compression the double layer of solid slip particles, so that the green compact may be solidified without the need for removing the water.

Abstract: A method for the production of hollow articles made of a particle-based material; e.g., ceramics and sintered metals. In accordance with one aspect of the invention, a thermally settable slurry containing a relatively high concentration of the particles is coated onto a prewarmed continuous surface in a relatively thin layer so that the slurry is substantially uniformly coated on the surface. The heat of the prewarmed surface conducts to the slurry to initiate a reaction which causes the slurry to set or harden in a shape conforming to the surface. The hardened configurations may then be sintered to consolidate the particles and provide a high density product.

Abstract: Low-firing glass ceramic green sheets useful in the production of glass ceramic multilayer substrates are prepared from a coarse raw powder material comprising a B.sub.2 O.sub.3 -containing glass powder. The coarse raw powder material is initially subjected to wet grinding, either in an alcohol-free organic solvent in the presence or absence of an organic binder, or in an alcohol-containing organic solvent in the presence of an organic binder, until the powder is comminuted to a particle size suitable for tape casting. The wet-ground powder is slurried with an organic solvent and an organic binder, and the slurry is cast into sheets. The resulting green sheets have improved elongation and can be punched to form fine through holes with a small pitch.