Abstract: The core/jacket catalyst molding with a core made from an inorganic support material and with a jacket made from a catalytically active material can be prepared by coextruding an aqueous molding composition which comprises the support material or a precursor thereof, with an aqueous molding composition which comprises the catalytically active material or a precursor thereof, then drying the coextrudate, and then calcining the dried coextrudate.

Abstract: It is directed to a silicon carbide-based porous body, wherein said body is a porous one which contains silicon carbide particles as an aggregate and metallic silicon, and has an oxygen-containing phase at the surfaces of silicon carbide particles and/or metallic silicon or in the vicinity of the surfaces thereof. The silicon carbide-based porous body contains refractory particles such as silicon carbide particles or the like and yet can be produced at a relatively low firing temperature at a low cost, has a high thermal conductivity, and is superior in oxidation resistance, acid resistance, chemical resistance to ash and particulates.

Abstract: A ceramic material suitable for use in production of paving tiles, construction tiles, flooring in offices, flooring in machinery plants and so forth is obtained by a method comprising steps of mixing defatted bran derived from rice bran with a thermosetting resin before kneading, subjecting a kneaded mixture thus obtained to a primary firing in an inert gas at a temperature in a range of 700 to 1000° C., pulverizing the kneaded mixture after the primary firing into carbonized powders, kneading the carbonized powders with which ceramic powders, a solvent, and a binder as desired are mixed into a plastic workpiece (kneaded mass), pressure-forming the plastic workpiece at pressure in a range of 10 to 100 MPa, and subjecting a formed plastic workpiece thus obtained again to firing in an inert gas atmosphere at a temperature in a range of 100 to 1400° C.

Abstract: A process produces a fiber-reinforced silicon carbide composite. The resulting composite has a high toughness where bundles of a reinforcing fiber are densely covered with glassy carbon derived from a resin to avoid deterioration of the strength, and it can easily be produced even in complicated shapes. Specifically, a fiber-reinforced silicon carbide composite is produced by preparing a fiber prepreg containing a powdered silicon and a resin and molding the prepreg to yield a green body having a desired shape, or laminating a fiber prepreg containing a resin and a woven fabric prepreg containing a powdered silicon and a resin in alternate order, and molding the laminate to yield a green body having a desired shape; carbonizing the green body at 900° C. to 1350° C. in an inert atmosphere; impregnating the carbonized body with a resin; firing the impregnated body again at 900° C. to 1350° C.

Abstract: The invention provides exemplary silicon carbide ceramic bodies and processes for making such ceramic bodies. In one embodiment, a raw batch for producing a ceramic body includes a silicon carbide slurry and agglomerates of particles defining a dry lubricant mixture. The mixture includes a binder and a dry lubricant such as graphite, with a majority of the agglomerates having a shape that is generally spherical.

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 present application is directed to ceramic compositions and, more specifically, to a silicon carbide composition and method of making it through liquid phase sintering. In one embodiment, the present invention is directed to an unsintered ceramic body including at least one liquid phase sintering aid. The unsintered ceramic body further includes a boron containing compound, a free carbon containing compound, and silicon carbide. In another embodiment, the present invention is directed to a method of making a sintered ceramic body. The method includes combining at least one liquid phase sintering aid, a boron containing compound, a free carbon containing compound, and silicon carbide to form a green ceramic, shaping the green ceramic into a ceramic body, and sintering the ceramic body.

Abstract: A powdery mixture of fine SiC powder with one or more oxide sintering additives of Al2O3, Y2O3, SiO2 and CaO is blended and uniformly dispersed in a polymeric SiC precursor to prepare a matrix-forming polymeric slurry. A preform of SiC fiber, which has quasi-stoichiometric composition with high crystallinity, is impregnated with the polymeric slurry and then hot-pressed at a temperature of 1600° C. or higher in presence of a liquid phase. Since the heat-resistant SiC fiber is used as strengthening fiber, the prepreg is sintered to a dense SiC composite excellent in mechanical properties by one-step hot-pressing.

Abstract: A composite body of silicon carbide having binderless, allotropic carbon granules distributed throughout is produced. The nominal size of the binderless allotropic carbon granules can range from 5 to 500 micrometers. The concentration of the binderless allotropic carbon particles can vary from 1.0 to 35.0 weight percent. The process to produce such a composite body is to sinter silicon carbide with binderless, carbon-yielding precursor granules. The composite body is utilized in tribological applications. The dense, impervious silicon carbide-binderless carbon composite exhibits excellent physical and tribological characteristics when used as a mechanical face seal, a sliding bearing arrangement, or some other rubbing component.

Abstract: A honeycomb structure having, in the axial direction, a number of through-channels separated by partition walls, which honeycomb structure contains refractory particles and a vitreous component and is porous. Although the honeycomb structure contains refractory particles such as silicon carbide particles or the like, it can be produced at a relatively low firing temperature; therefore, the honeycomb structure has a low production cost and a high yield and can be provided at a low price.

Abstract: 12A high temperature gas turbine component includes an inner core made of a monolithic ceramic material embedded within an outer CMC shell. The inner core may be formed with a through hole, blind hole, wear pads and the like. A method of making the bushing includes the steps of a) forming an inner core of silicon nitride or silicon carbide; and b) applying a ceramic matrix composite material over substantially all of the inner core.

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: A composite body of silicon carbide having binderless, allotropic carbon granules distributed throughout is produced. The nominal size of the binderless allotropic carbon granules can range from 5 to 500 micrometers. The concentration of the binderless allotropic carbon particles can vary from 1.0 to 35.0 weight percent. The process to produce such a composite body is to sinter silicon carbide with binderless, carbon-yielding precursor granules. The composite body is utilized in tribological applications. The dense, impervious silicon carbide-binderless carbon composite exhibits excellent physical and tribological characteristics when used as a mechanical face seal, a sliding bearing arrangement, or some other rubbing component.

Abstract: The present invention provides a carbon heating element having an arbitrary specific resistance and an arbitrary shape which are arbitrary necessary as a heating element, and a method of producing the same. The carbon heating element is obtained by uniformly dispersing one or at least two metal or metalloid compounds into a composition having shapability and showing a high yield of a carbon residue after firing, shaping the dispersed material-containing mixture thus obtained, and firing the shaped material under a nonoxidizing atmosphere.

Abstract: SiC—C/C composite materials having a suitable kinetic coefficient of friction, good corrosion resistance in strongly oxidizing and corrosive environments, good creep resistance and spalling resistance, and high hardness. The materials are hardly oxidized or abraded even when exposed to high temperatures, while maintaining the excellent impact resistance and light weight of C/C composites. Molten metal pumps using the materials are provided from which components do not dissolve into the molten metal even when used in molten metal and have sufficient thermal impact resistance and oxidation resistance.

Abstract: Improved silicon carbide composites made by an infiltration process feature a metal phase in addition to any residual silicon phase. Not only are properties such as mechanical toughness improved, but the infiltrant can be so engineered as to have much diminished amounts of expansion upon solidification, thereby enhancing net-shape-making capabilities. Further, multi-component infiltrant materials may have a lower liquidus temperature than pure silicon, thereby providing the practitioner greater control over the infiltration process. In particular, the infiltration may be conducted at the lower temperatures, where low-cost but effective bedding or barrier materials can terminate the infiltration process once the infiltrant has migrated through the permeable mass up to the boundary between the mass and the bedding material.

Abstract: A method of producing an optical element forming die to form an optical element by pressing a glass material softened with heat, including a first process of producing a primary processed product having a volume resistance value Z (0<Z≦1 (&OHgr;·cm) by sintering ceramic powders; and a second process of forming the optical element forming die by processing the primary processed product.

Abstract: A fiber-reinforced silicon carbide composite is produced by preparing a fiber prepreg containing a powdered silicon and a resin and molding the prepreg to yield a green body having a desired shape, or laminating a fiber prepreg containing a resin and a woven fabric prepreg containing a powdered silicon and a resin in alternate order and molding the laminate to yield a green body having a desired shape; carbonizing the green body at 900° to 1350° C. in an inert atmosphere; subjecting the carbonized body to reaction sintering at a temperature of 1300° C. or more in vacuo or in an inert atmosphere to form open pores; and infiltrating molten silicon into the sintered body having open pores at a temperature of about 1300° to 1800° C. in vacuo or an inert atmosphere.

Abstract: A method of manufacturing a preform for compounding use which, is to be impregnated with a molten metal to be compounded with a matrix material, is provided. The method includes the step of mixing short fibers, ceramic particles and a binder material together to make a mixture. The average of lengths of the short fibers is 100 to 200 &mgr;m while the volumetric percentage of the short fibers is 1 to 7%. The content of the binder material in the mixture is 0.3 to 5.0 mass %. The method includes also the steps of forming the mixture so as to have a predetermined shape, and sintering the mixture at a temperature of 1000 to 1150° C. to form the preform. Thus, it is restrained that the preform is deformed or an un-reinforced region is formed in the compounded portion.

Abstract: This invention relates to an aging resistant SiC igniter having a second layer of recrystallized SiC within the body.

Abstract: A process for producing a SiC ceramic microtube, comprising the steps of oxidizing the surface of an organosilicon polymer to become infusible by exposure to an ionizing radiation, extracting the uncrosslinked central portion of the fiber with an organic solvent to make a hollow silicon polymer fiber, and firing it in an inert gas so that it acquires a ceramic nature.

Abstract: A process for forming a porous silicon nitride-silicon carbide body, the process comprising (a) forming a plasticizable batch mixture comprising (1) powdered silicon metal; (2) a silicon-containing source selected from the group consisting of silicon carbide, silicon nitride and mixtures thereof; (3) a water soluble crosslinking thermoset resin having a viscosity of about 50-300 centipoise; and, (4) a water soluble thermoplastic temporary binder; (b) shaping the plasticizable batch mixture to form a green body; (c) drying the green body; (d) firing the green body in nitrogen at a temperature of 1400° C. to 1600° C. for a time sufficient to obtain a silicon nitride-silicon carbide structure.

Abstract: A brake unit having a brake disc of ceramic and a hub of a different material, which radially overlap one another with their mutually facing rims and are mechanically joined by a wreath-type rim of mounting bolts that axially penetrate the overlapping rims. The mounting bolts are uniformly included in the transmission of torque. Entrainment bores or slots provided in the brake disc are plastically lined with a metal or plastic sleeve, or the disc material is formed specifically to certain areas in this region as a plastically deformable C/C structure. A method is disclosed for manufacturing a partially ceramized molded article, in particular a brake disc having a C/C structure in the area of the entrainment bores or slots. A completely non-metallic brake unit and a method for its manufacture are also disclosed.

Abstract: A honeycomb structure made of a silicon carbide-based porous body and having a number of through-holes extending in the axial direction, separated by partition walls.

Abstract: A method for producing shaped articles of ceramic composites provides a high degree of dimensional tolerance to these articles. A fiber preform is disposed on a surface of a stable formed support, a surface of which is formed with a plurality of indentations, such as grooves, slots, or channels. Precursors of ceramic matrix materials are provided to the fiber preform to infiltrate from both sides of the fiber preform. The infiltration is conducted under vacuum at a temperature not much greater than a melting point of the precursors. The melt-infiltrated composite article substantially retains its dimension and shape throughout the fabrication process.

Abstract: A fiber-composite material (7) is comprised of a yarn aggregate (6) in which yam (2A, 2B) including at least a bundle (3) of carbon fiber and a carbon component other than carbon fiber is three-dimensionally combined and integrally formed without separation from each other; and a matrix made of Si—SiC-based materials (4A, 4B, 5A, 5B) filled between the yarn (2A, 2B) adjacent to each other within the yarn aggregate (6).

Abstract: The invention comprehends a silicon nitride sintered body having consistent qualities, a process for producing the same, a ceramic heater employing the silicon nitride sintered body as a substrate and a glow plug containing the ceramic heater as a heat source. In the production of a silicon nitride sintered body through a hot press method, a sintering aid protecting agent is added to the raw material. The employable protecting agents are metallic elements such as Ta, W and Mo and compounds of the metallic elements such as nitrides and silicides. Conversion of these elements and compounds to carbides occurs preferentially to reduction of the sintering aid. Thus, it becomes possible to suppress reduction of the sintering aid in a reducing atmosphere formed, for example, of carbon monoxide, which is generated particularly when a graphite pressing die is employed.

Abstract: It is an object of the present invention to provide a method for simply producing a high purity silicon carbide sintered body having no remaining metal silicon and excellent heat resistance. A method for producing a silicon carbide sintered body of the present invention comprises the steps of: preparing a slurry by dispersing silicon carbide powder in a solvent; forming a molded body by pouring the slurry into a mold and effecting calcination for the slurry in a vacuum atmosphere or in an inert gas atmosphere; and sealing pores within the calcined molded body by impregnating the pores with high purity metal silicon molten by heating, and allowing the high purity metal silicon and carbon contained in the molded body to react on each other in the pores so as to produce silicon carbide.

Abstract: A mixture is formed that comprises at least some to about 10 wt % boron nitride and silicon. A body comprising a component that is wetted by or reacts with silicon is contacted with the mixture and the contacted body is infiltrated with silicon from the mixture.

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: 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: A method comprising incorporation of an inorganic polymer precursor of a grain growth inhibitor into nanostructured materials or intermediates useful for the production of nanostructured materials. The precursor/nanostructured material composite is optionally heat treated at a temperature below the grain growth temperature of the nanostructured material in order to more effectively disperse the precursor. The composites are then heat treated at a temperature effective to decompose the precursor and to form nanostructured materials having grain growth inhibitors uniformly distributed at the grain boundaries. Synthesis of the inorganic polymer solution comprises forming an inorganic polymer from a solution of metal salts, filtering the polymer, and drying. Alloying additives as well as grain growth inhibitors may be incorporated into the nanostructured materials.

Abstract: A composite material article reinforced with high strength short graphite fibers and having a matrix substantially consisting of silicon carbide is prepared which has an elongation at break of 0.25 to 0.5% and thus exhibits quasi-ductile failure behavior. The short reinforcing graphite fibers are enclosed by at least two shells of graphitized carbon which have been obtained by impregnation with carbonizable impregnating agents and subsequent carbonization. The shell closest to the graphite fibers contains no cracks. The outermost shell is partially converted into silicon carbide. The starting material used comprises long or short fiber prepregs, which are first carbonized, then subjected at least once to an operation consisting of impregnation with a carbonizable impregnating agent and recarbonization, then graphitized at a temperature of up to a maximum of 2400° C. and then comminuted to yield a dry material for the production of a precursor article.

Abstract: A process for producing a body having a porous matrix of at least one recrystallized ceramic material, or for producing a similar fiber-reinforced body, includes shaping a raw material batch which contains a raw material powder and then sintering. A raw material powder is used which has grain size distribution of a fine grain fraction of an average grain size of at most approximately 2 &mgr;m and a coarse grain fraction of an average grain size of approximately 1.5 &mgr;m to approximately 30 &mgr;m, and the sintering process is carried out at a temperature of at most approximately 1,800° C. Because of the selected grain sizes and grain size distributions, the sintering process can be carried out at lower temperatures. In particular, reinforcing fibers can be worked in which can withstand higher sintering temperatures. By defining the grain size of the powder, a porosity can also be set which permits a good impregnating with organic and/or inorganic substances.

Abstract: A sintered silicon carbide containing nitrogen is obtained by sintering a mixture of a powder of silicon carbide and a nonmetallic auxiliary sintering agent. The sintered silicon carbide has a density of 2.9 g/cm3 or more and contains 150 ppm or more of nitrogen. The sintered silicon carbide preferably has a volume resistivity of 1 &OHgr;·cm or less and contains &bgr;-silicon carbide in an amount of 70% or more of total silicon carbide components. Nitrogen can be introduced into the sintered silicon carbide by adding a nitrogen source, for example, an amine such as hexamethylenetetramine, ammonia, and triethylamine in the production of the powder of silicon carbide which is used as the material powder for producing the sintered silicon carbide or by adding the nitrogen source in combination with the nonmetallic auxiliary sintering agent in the production of the sintered silicon carbide.

Abstract: A heater member is formed of a silicon carbide sintered body. The silicon carbide sintered body includes silicon carbide powder and a non-metal-based sintering auxiliary, and is obtained by sintering a homogeneous mixture of the silicon carbide powder and the non-metal-based sintering auxiliary. The silicon carbide sintered body is formed to have a density of 2.9 g/cm3 or higher. Further, the silicon carbide sintered body is preferably obtained by hot pressing, and also preferably has physical properties of a volume resistivity of 10 &OHgr;cm or less and a total content of impurity elements of 1 ppm or less.

Abstract: A process is described for producing a conductive sintered body based on silicon carbide, in which a) silicon carbide particles, optionally pretreated with a surface modifier, are dispersed in an aqueous and/or organic medium and positive or negative surface charges are generated on the silicon carbide particles by adjustment of the pH of the dispersion obtained; b) carbon black and boron carbide are mixed in as sintering aids, where at least the carbon black particles have a surface charge opposite to the surface charge of the silicon carbide particles and the boron carbide can also be added, completely or in part, at a later point in time (stage c′)); c) the slip thus obtained is shaped directly to form a green body or c′) a sinterable powder is isolated from the slip obtained and is shaped to form a green body, where the above boron carbide can also be added to this sinterable powder; and d) the green body obtained is subjected to pressureless sintering to form a sintered body in essential

Abstract: A ceramics dress substrate of the present invention capable of both performances of cutting a cut material with a high accuracy and dressing a diamond cutting grindstone with an excellent cutting property and an reduced wearing amount of the grindstone. This ceramics dress substrate comprises sintering a mixture of ceramics grinding particles and a silicate mineral, The ceramics grinding particles are preferably uniformed and have a scratch hardness ranging from 6 to 10. Alumina grinding particles, silicon carbide and mullite are preferably used as the ceramics grinding particles, and a kaolin mineral, pyrophyllite, montmorillonite, sericite, talc and chlorite are preferably used as the silicate mineral. The ceramics dress substrate is preferably coated with glass.

Abstract: A method of making a whisker-reinforced ceramic body by hot pressing a preform to a disc, cutting the disc into blanks and grinding the blanks to bodies of desired shape and dimension is disclosed. The preform is prepared by dispersing 10-60% by volume of a ceramic powder mixture containing conventional sintering aids and/or grain growth inhibitors in water or an organic solvent adding 1-15 wt-% starch to the dispersion; pouring the dispersion into a mold with desired shape; heating the suspension to 50°-100° C. for 2-4 hours while covering the mold to avoid water evaporation to form a preform; removing the preform from the mold; and presintering the preform in air for 10 h at a maximum temperature of about 600° C.

Abstract: According to the method of the present invention, joining a first bi-element carbide to a second bi-element carbide, has the steps of: (a) forming a bond agent containing a metal carbide and silicon; (b) placing the bond agent between the first and second bi-element carbides to form a pre-assembly; and (c) pressing and heating the pre-assembly in a non-oxidizing atmosphere to a temperature effective to induce a displacement reaction creating a metal silicon phase bonding the first and second bi-element carbides.

Abstract: A method and crucible for annealing SiC at high temperatures. The crucible s a vessel having a peripheral wall, at least two compartments separated by an inner wall within the peripheral wall and a lid which separates the compartments from the crucible surroundings while providing a passageway between the compartments. The peripheral wall, inner wall and lid are composed of materials capable of withstanding annealing temperatures. The process disposes an SiC wafer in one of the compartments and SiC powder disposed in another of the compartments. The SiC powder is present to hinder SiC wafer decomposition during annealing of the SiC wafer. The crucible is then heated to a temperature sufficient anneal the SiC wafer, preferably after evacuating air and flowing an inert gas in and around the crucible.

Abstract: The present invention provides a dense SiC-infiltrated composite material or a dense carbon-fiber-reinforced SiC-infiltrated composite material and a dense SiC-infiltrated composite material with granular carbon dispersed therein that are unlikely to bond to a carbon crucible and that have excellent heat and oxidation resistance. This composite material can be obtained by infiltrating molten carbon-silicide of Mo that is approximately expressed as Mo.sub.3 Si.sub.2 C or a eutectic mixture of carbon-silicide and silicon carbide into a silicon-carbide-based preform having 10 to 60 vol. % of continuous voids and then cooling and solidifying the melt.

Abstract: A process for producing a bonded article of ceramic bodies comprising steps of: machining the ceramic bodies to be bonded to form machined surfaces with average surface roughnesses (Ra) of not more than 0.2 .mu.m and flatnesses of not more than 0.2 .mu.m; applying solution containing a bonding aid on at least one of the machined surfaces; contacting the machined surfaces with each other to produce an assembly; and subjecting the assembly to a heat treatment to produce the bonded article. The roughnesses and the flatnesses may preferably be not more than 0.1 .mu.m. The bonding aid may preferably be a sintering aid applicable to at least one of the ceramic bodies. The ceramic bodies may preferably be one or more material selected from a group consisting of aluminum nitride and silicon nitride. The bonding aid may preferably be one or more bonding aid selected from a group consisting of a substance of yttrium and a substance of ytterbium.

Abstract: A high strength, high creep resistant, boron-doped, silicon carbon fiber having no boron nitride coating, originally formed by sintering, is produced by exposing the fiber to a nitrogen atmosphere at a temperature equal to or preferably elevated above the sintering temperature and also exposing the fiber to a carbon monoxide-containing atmosphere at a temperature sufficient to remove boron and boron nitride. The nitrogen atmosphere step may be performed before or after the carbon monoxide-containing atmosphere step. The resulting, uncoated SiC fibers have tensile strengths greater than approximately 2.0 GPa and Morscher-DiCarlo BSR test creep resistance M values greater than approximately 0.75 at 1400 degrees C. for one hour in argon. The method is applicable to non-sintered fibers as well, in which case the nitrogen exposure is carried out at between approximately 1750 to 2250 degrees C. and the carbon monoxide exposure is carried out at between approximately 1600 to 2200 degrees C.

Abstract: A silicon carbide sintered body according to the present invention is a silicon carbide sintered body having a density of 2.9 g/cm.sup.3 or higher, obtained by means of hot pressing a mixture of silicon carbide powder and a non-metal-based sintering additive such as an organic compound which produces carbon upon heating at a temperature of 2,000.degree. C. to 2,400.degree. C. and under a pressure of 300 to 700 kgf/cm.sup.2 in a non-oxidizing atmosphere. It is preferable that the silicon carbide powder have an average particle diameter of from 0.01 to 10 .mu.m and that the non-metal sintering additive be a resol type phenol resin. The present invention is to provide a silicon carbide sintered body of high quality which has a high density, a high purity, and a high electrical conductivity and which is useful for semiconductor manufacturing industry.

Abstract: A method of forming a refractory die, and a method for forming a metal article using a refractory die. The refractory die is formed of a ceramic material by casting a slurry containing particles of the ceramic material onto a mold. Then the mold is vibrated while excess liquid medium from the slurry is simultaneously removed, whereby ceramic particles continue to flow into surface details of the mold. The present method of forming a refractory die minimizes drying and firing shrinkage, and even adjusts for drying and firing shrinkage by inclusion of kyanite in the refractory die. According to the method of forming a metal article, a particulate material containing powdered metal is compressed on a refractory die at an elevated temperature and pressure. The consolidated particulate material is differentially cooled, wherein a first, low mass portion contacting the refractory die is cooled more quickly than an opposing, high mass portion of the consolidated body.

Abstract: The invention includes a process for producing a reaction bonded silicon carbide composite reinforced with coated silicon carbide fibers which is suitable for high temperature applications. The process includes the steps of coating SiC fibers with AlN, BN or TiB.sub.2 ; treating the coated fibers with a mixture of SiC powder, water and a surfactant; preparing a slurry comprising SiC powder and water; infiltrating the coated fibers with the slurry to form a cast; drying the cast to form a green body; and reaction bonding the green body to form a dense SiC fiber reinforced reaction bonded matrix composite.The invention further includes a SiC fiber reinforced SiC composite comprising a reaction bonded SiC matrix, a SiC fiber reinforcement possessing thermal stability at high temperatures and an interface coating on the fibers having chemical and mechanical compatibility with the SiC matrix and with the SiC fibers.

Abstract: A process is provided for permanently joining at least two structural components together to form a molded body, in which a carbon-containing paste is introduced between the structural components to be joined and heated to form a carbon skeleton. This skeleton is then infiltrated with silicon at a temperature above 1,410.degree. C. to form silicon carbide. As one of the structural components, a carbon fiber-reinforced component with a system of microcracks is used. One of the structural components is aligned with the other structural component in such a way as to leave a joint gap. For cases in which the width, defined as the distance between the two surfaces to be joined, is .ltoreq.80 .mu.m, the joint gap is filled with a paste which contains an organic, carbon-containing binder with a carbon content of at least 30 wt. % and carbon powder with a particle size of less than 15 .mu.m. In cases where the width of the gap is more than 80 .mu.

Abstract: This invention pertains to a method for production of polycrystalline ceramic fibers from silicon oxycarbide (SiCO) ceramic fibers wherein the method comprises heating an amorphous ceramic fiber containing silicon and carbon in an inert environment comprising a boron oxide and carbon monoxide at a temperature sufficient to convert the amorphous ceramic fiber to a polycrystalline ceramic fiber. By having carbon monoxide present during the heating of the ceramic fiber, it is possible to achieve higher production rates on a continuous process.

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.