Abstract: A SiC based sinterable powder mixture comprising, by dried weight of said powder: a) a mineral content comprising—silicon carbide (SiC) particles, —mineral boron compound particles, the powder comprising at least 50% by weight of SiC and the total mineral content of the powder being at least 90% by weight, b) at least a water insoluble carbon-containing source, in particular a carbon containing resin, the powder comprising at least 1% by weight, and preferably less than 10% by weight, of said water insoluble carbon-containing source, wherein the average particle size of said sinterable powder is comprised between 0.5 to 2.0 micrometers.

Abstract: The present invention relates to extrudable ceramic masses and other masses which set as a result of baking or sintering, which masses comprise specific additives based on water-soluble cellulose ethers, an extrusion process, the extrudates and their use.

Abstract: A method and product made by using a polymeric ceramic precursor to synthesize dense, crack-free bulk ceramics in a technique using a sacrificial mold provides a ceramic structure for many technical, medical and industrial applications. The novel process uses an open cell material as a sacrificial mold to shape a ceramic precursor during curing. The cured ceramic green body can be machined and shaped to form the desired ceramic structure prior to final pyrolysis. The open cell material forms gas release paths to release large amount of gases generated during the pyrolysis of the cured ceramic precursor. After pyrolysis, an intact, dense, crack-free ceramic structure with high purity, strength and durability is obtained. Uses of the present invention include, but are not limited to, bulk ceramic parts, ceramic crucibles, a replacement material in some applications involving glass, silicon carbides, silicon nitrides, hafnium carbide and the like.

Abstract: The invention provides Al2O3 dispersion-strengthened Ti2AlN composites, wherein Ti2AlN matrix and Al2O3 strengthening phase both are reactively formed in situ. The volume fraction of Al2O3 is 5% to 50%; the particle size of Al2O3 ranges from 500 nm to 2 ?m, with the mean size of Al2O3 particles about 0.8 ?m to 1.2 ?m; the shape of Ti2AlN grain is plate-like about 80 nm to 120 nm thick and 0.5 ?m to 2 ?m long. The composites exhibit excellent deformability at high temperature under compression and flexure stresses, and possess excellent oxidation resistance at 1100° C. to 1350° C. for long time (100 h). The composites show typical metallic conductor behavior and the electrical resistivity at room temperature is 0.3 to 0.8 ??·m. The invention also provides a method for preparing the same: First, nanoparticles in Ti—Al binary system were prepared in continuous way by hydrogen plasma-metal reaction (HPMR) using Ti—Al alloy rods with Al content 20% to 60% by atom, or pure Al rods and pure Ti rods.

Abstract: An object of the present invention is to lower the sintering temperature required for a sintered body of yttrium-aluminum garnet, to improve the corrosion resistance of the sintered body and to prevent the reduction of the transmittance thereof. A sintered body of yttrium-aluminum garnet is produced from a source compound for yttrium and a source compound for aluminum using aluminum nitride as a sintering aid. It maybe considered that aluminum nitride reacts with alumina and yttria to generate liquid phase and to reduce the sintering temperature during the sintering process.

Abstract: A method for making a crystallized ceramic body containing a two phase composite comprising an alpha prime SiAlON phase that contains ytterbium and a beta prime SiAlON phase, the process includes the steps of: blending together a starting powder mixture that upon densification forms the SiAlON ceramic, the starting powder includes at least about 70 weight percent silicon nitride powder wherein the silicon nitride powder contains beta silicon nitride in an amount less than or equal to about 1.

Abstract: A silicon nitride porous body (5) obtained by nitriding a molded body having metallic silicon (3) as a main component, the porous body having a porous structure with an average pore diameter of 3 ?m or above, and wherein the total content of silicon and nitrogen is 95% or above and the nitridation ratio of silicon is 90% or above. The silicon nitride porous body has a porous structure with a large average pore diameter, with a test specimen cut out from the porous body exhibiting large thermal conductivity and a small thermal expansion coefficient, and can be suitably used in a component for purifying gas and/or solution such as a ceramic filter.

Abstract: A silicon nitride porous body which is obtained by nitriding a molded body having metallic silicon as a main component and by performing a high temperature heating treatment at a temperature higher than the nitriding temperature, and which has a porous structure with an average pore diameter of 3 ?m or above, and contains at least one kind of element selected from the group consisting of the groups 2A, 3A, 3B inclusive of lanthanoid elements, and 4B. The silicon nitride porous body has a porous structure with a large average pore diameter, a test specimen cut out from the porous body exhibiting a high thermal conductivity and a small thermal expansion coefficient, and can be suitably used in a component for purifying gas and/or solution such as a ceramic filter.

Abstract: The present invention relates to a silicon carbide-boron nitride composite material, which synthesised according to an in-situ chemical reaction between silicon nitride, boron carbide and carbon, and which contains fine boron nitride particles dispersed in a silicon carbide matrix, wherein aforementioned composite material is obtained by molding a powder mixture containing each of the components required in the in-situ reaction and sintering the mixture.

Abstract: The invention provides a fiber-reinforced composite ceramic containing high-temperature-resistant fibers, in particular fibres based on Si/C/B/N, which are reaction-bonded to a matrix based on Si, which is produced by impregnating fiber bundles of Si/C/B/N fibers with a binder suitable for pyrolysis and solidifying the binder, if desired subsequently conditioning the fiber bundles with an antisilicization layer suitable for pyrolysis, for example phenolic resin or polycarbosilane, subsequently preparing a mixture of fiber bundles, fillers such as SiC and carbon in the form of graphite or carbon black and binders, pressing the mixture to produce a green body and subsequently pyrolysing the latter under reduced pressure or protective gas to produce a porous shaped body which is then infiltrated, preferably under reduced pressure, with a silicon melt.

Abstract: A high thermal conductive silicon nitride base sintered body which comprises a phase comprising crystal grains of silicon nitride and a grain boundary phase containing a compound of at least one element selected from the group consisting of yttrium and the lanthanide elements in an amount of 1 to 20% by weight in terms of oxide amount, and contains free silicon dispersed therein in an amount of 0.01 to 10% by weight based on the whole. This high thermal conductive silicon nitride base sintered body has high strength coupled with high thermal conductivity and thus is useful not only as various parts for semiconductor devices, such as radiating insulating substrates, but as various structural parts for machines, OA apparatuses, etc.

Abstract: A process for nitriding materials containing silicon to form a silicon nitride material predominantly in the alpha phase is disclosed which includes nitriding the silicon-containing material by (a) heating the silicon-containing material in an atmosphere containing at least hydrogen in the temperature range of about 0.degree. C. to about 800.degree. C. and (b) thereafter, nitriding the silicon-containing material by subjecting the silicon-containing material to a nitriding atmosphere containing at least nitrogen gas in the temperature range of from about 1000.degree. C. to about 1450.degree. C. to effect nitriding.

Abstract: A silicon nitride reaction-sintered body having a high mechanical strength without surface working can be produced by (1) forming a silicon powder mixture of at least two types of silicon powders having substantially independent particle size distribution ranges into a green body, the silicon powder mixture having an average particle size ranging from 5 .mu.m to 300 .mu.m; (2) heating the green body in a nitrogen-containing atmosphere for nitrogenation; and (3) sintering the nitrogenated green body at a temperature of 1900.degree. C. or higher.

Abstract: Sintered reaction-bonded silicon nitride components, e.g., automotive components, are made by forming a powder mixture comprising silicon and oxide or oxide precursor additives. These additives comprise alumina and a calcium compound. The powder is formed into a preform, the silicon is reacted with nitrogen in a nitriding process to form silicon nitride, and the so-formed silicon nitride is sintered.

Abstract: A method of producing spherical particles made from inorganic oxides by sol/gel conversion in which a sol is sprayed upwards from below into a reaction zone containing a reactant gas in such a way that the sol does not split up into individual droplets until immediately before or as it enters the reaction zone, and the resulting droplets fly through the reaction zone along a curved trajectory during which they are presolidified, the presolidified droplets being caught in a trap. Also described are spherical particles made from inorganic oxides with a narrow pore diameter distribution and a high resistance to wear which are suitable for use as catalysts, catalyst supports, adsorbents drying agents or ion exchange materials.