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: The present invention provides: a fabrication method of a silicon carbide sintered body, including a step of fabricating a mixed powder slurry by dissolving or dispersing silicon carbide powder, at least one organic material composed of a nitrogen source, and at least one organic material composed of a carbon source or carbon powder in a solvent, a step of fabricating a green body by pouring the mixed powder slurry into a mold and drying and a step of filling pores in the green body by immersing the green body in high purity metallic silicon that has been heated to 1450 to 1700° C. in a vacuum atmosphere or inert gas atmosphere and melted, and generating silicon carbide by reacting silicon sucked up into the pores in the green body by capillary action with free carbon in the green body; and a silicon carbide sintered body obtained by a reaction sintering method, having a density of 2.90 g/cm3 or more and a volume resistivity of 100 &OHgr;·cm or less, and containing nitrogen at 150 ppm or more.

Abstract: A method for preparing a refractory carbide component includes the steps of providing a carbon rich polymer precursor to silicon carbide and excess carbon, determining an amount of excess carbon in the carbon rich polymer precursor, combining the carbon rich polymer precursor with a selected amount of refractory metal to form a precursor/metal mixture, the selected amount being selected so as to provide stoichiometrically equivalent amounts of the excess carbon and the refractory metal, forming the mixture into a preform of a propulsion component, and heating the preform so as to thermally degrade the carbon rich polymer precursor to produce the silicon carbide and the excess carbon, the excess carbon and the refractory metal reacting to form refractory metal carbide and provide the refractory carbide component.

Abstract: Process for producing hollow bodies comprising fiber-reinforced ceramic materials, where mold cores whose shape corresponds to that of the hollow spaces are produced in a first step, at least one mold core together with a press moulding composition or formable fiber composition are introduced into a mold, where the press moulding composition comprises carbon fibers and/or carbon filaments and thermally curable carbonizable binders, in such a way that the position of the cores corresponds to the desired position of the hollow spaces to be formed in a second step, the composition is cured in a third step by heating to a temperature of from 120° C. to 280° C., to give a green body, the strengthened green body is carbonized and or graphitized in a fourth step by heating in a nonoxidizing atmosphere to a temperature of from about 750° C. to about 2400° C.

Abstract: SiC fiber-reinforced SiC-matrix composite has the structure that SiC filaments are inserted into SiC matrix formed as a pyrolysis product of polyvinyl-silane (PVS) infiltrated into openings of said SiC filaments. PVS as a polymeric SiC precursor has structural units (a) and (b) at an a/b ratio of 1. A SiC fiber preform is impregnated with PVS slurry in an open or vacuum atmosphere, preheated at 300-400° C. in an inert gas atmosphere to moderate PVS to a viscous or semi-cured state, and then pyrolyzed in an argon atmosphere under application of a unidirectional pressure. A product is SiC fiber-reinforced SiC-matrix composite excellent in mechanical strength and high-temperature property with high density. The SiC composite is further densified by infiltration of PVS slurry suspending fine SiC particles therein or by repetition of impregnation with sole PVS and pressure-less pyrolysis after the pressurized pyrolysis.

Abstract: A method for preparing a refractory carbide component includes the steps of providing a carbon rich polymer precursor to silicon carbide and excess carbon, determining an amount of excess carbon in the carbon rich polymer precursor, combining the carbon rich polymer precursor with a selected amount of refractory metal to form a precursor/metal mixture, the selected amount being selected so as to provide stoichiometrically equivalent amounts of the excess carbon and the refractory metal, forming the mixture into a preform of a propulsion component, and heating the preform so as to thermally degrade the carbon rich polymer precursor to produce the silicon carbide and the excess carbon, the excess carbon and the refractory metal reacting to form refractory metal carbide and provide the refractory carbide component.

Abstract: Transition metal-containing ceramic or carbonaeous material are formed from novel linear polymers containing a random distribution of repeating acetylenic units, organotransition metal complexes, siloxane, boron, silicon, and/or carborane-siloxane units. The precursor thermosets are formed by crosslinking of the linear polymers through the acetylenic units in the polymer backbone. The ceramics may also be formed directly by pyrolysis of the linear polymers. The preceramic polymers are potentially useful for fabricating ceramic fibers and composite materials having enhanced strength, hardness and toughness as well as superior mechanical, optical, electrical and/or magnetic properties.

Abstract: A method for making a boron carbide containing ceramic involves pyrolyzing a precursor having one or more monosubstituted decaboranyl groups and at least one substituting group containing carbon. The precursor may be molecular, for example comprising two decaboranyl groups linked by a single substituting group, or polymeric, in which case the decaboranyl groups are part of the pendant group of the polymer while a portion of the substituting group makes up the polymer backbone. In either case, the substituting group may be a hydrocarbon, in which case boron carbide may be formed. Alternatively, the substituting group may contain carbon and another ceramic forming element (i.e., other than boron or carbon), such as silicon, nitrogen, or phosphorous, in which case a composite including boron carbide is formed.

Abstract: A process for producing crack-free shaped ceramic bodies based on Si/C/N by hot pressing of crosslinked polysilazane powder and subsequent pyrolysis of the hot-pressed shaped body employs a pressing temperature higher than the temperature maximum of the TMA curve of the optimally crosslinked polymer.

Abstract: This invention pertains to a method of forming a fiber-reinforced ceramic matrix composite comprising: (a) impregnating a ceramic fiber coated with at least one layer binary coating comprised of boron nitride and silicon nitride wherein the silicon nitride is applied over the boron nitride with a preceramic composition comprising a curable preceramic polymer; (b) forming the impregnated fibers into a desired shape; (c) curing the formed impregnated fibers; (d) heating the cured impregnated fibers of (c) to a temperature of at least 1000° C. in an inert atmosphere for a time effective to convert the preceramic polymer to a ceramic.

Abstract: Polycarbosilane is mixed with 5-35 wt % of polyvinylsilane to prepare a silicon-base polymer blend which is impregnated in silicon carbide fibers or fabrics to form a preceramic molding body which is exposed to an ionizing radiation to be rendered curing and then fired in an inert gas to produce a composite in which the silicon carbide matrix is reinforced with the silicon carbide fibers.

Abstract: There is disclosed a hybrid treatment into which CVI treatment and PIP treatment are combined. A dense matrix is formed around a ceramic fiber by the CVI treatment, and a gap in the matrix is infiltrated/filled well with the matrix by the PIP treatment, so that hermetic properties are enhanced. Moreover, when a volume ratio of the matrix by the CVI treatment in the total matrix is set to about 5% or more, about 80% or less, fine cracks are present in the matrix by the PIP treatment, so that a binding force of the ceramic fiber is weakened, and Young's modulus can be reduced. As a result, a thermal stress is alleviated and a resistance to thermal shock is enhanced.

Abstract: A fracture-resistant, thermally stable intake or exhaust valve for an internal combustion (IC) engine. The valve has a stem portion and a head portion, both of which are formed of fiber reinforced ceramic matrix composite (FRCMC) material. This FRCMC material generally includes a polymer-derived ceramic resin in its ceramic state, fibers, and filler materials. Employing FRCMC material to form the valve is advantageous as FRCMC material is highly temperature resistant and temperature stable, thereby allowing for increased engine operating temperatures. FRCMC material is also ductile, thus making the valve fracture resistant. The FRCMC material is also flaw-insensitive in that any flaw within the structure of the valve will not result in cracking and failure. In addition, FRCMC valves are considerably lighter than the existing metal valves. This provides an opportunity to reduce the weight of the overall valve train, thereby increasing engine performance.

Abstract: This invention relates to a new class of novel inorganic-organic hybrid ceramics that are formed from novel linear polymers of varying molecular weight and varying carborane content.

Abstract: A process for producing polycrystalline silicon carbide by heating an amorphous ceramic fiber that contains silicon and carbon in an environment containing boron oxide vapor. The boron oxide vapor is produced in situ by the reaction of a boron containing material such as boron carbide and an oxidizing agent such as carbon dioxide, and the amount of boron oxide vapor can be controlled by varying the amount and rate of addition of the oxidizing agent.

Abstract: A fiber-bond type ceramic material 4 is produced by using as raw material fibers 1 inorganic fibers of Si—M—C—O synthesized by melt spinning polycarbosilane, then infusibilizing the produced threads, and firing the set threads, forming from the raw material fibers a woven fabric 2 having all the fibers thereof extended perpendicularly or obliquely relative to the direction of compression during the course of a hot-press fabrication at a weaving step 12, heat-treating the woven fabric in the air, thereby preparing a woven fabric of oxidized fibers 3 provided with an oxide layer on the surface thereof at an oxidizing step 14, and subjecting the woven fabric of oxidized fibers to a hot-press fabrication while compressing the fabric in the direction of the compression thereby causing the oxide layers on the surface to adhere fast to each other and form a matrix at a hot-press step 16.

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 highly heat-resistant sintered SiC fiber bonded material free of a decrease in strength and less breakable at an ultra-high temperature over 1,400.degree. C., comprising inorganic fibers which are composed mainly of a sintered SiC crystal, contain at least one kind of metal atoms selected from the class consisting of metal atoms of the 2A, 3A and 3B groups of the periodic table and are bonded nearly in the close-packed structure and 1 to 50 nm boundary layers composed mainly of carbon which are present at the interface of fibers, the less breakable highly heat-resistant sintered SiC fiber-bonded material having a density of at least 2.7 g/cm.sup.3 and an elastic modulus of at least 200 GPa, and a process for the production thereof.

Abstract: The present invention relates to a method for the formation of amorphous boron silicon oxycarbide fibers and crystalline boron-doped silicon carbide fibers wherein the method comprises preparing a blend of a siloxane resin and a carborane-siloxane oligomer, forming the blend into green fibers, and then curing and pyrolyzing the fibers.

Abstract: A process for modifying the surface of a base metal formed from a hard material instead of forming a coating film thereon comprises compacting a powder of a hard material, baking the compacted product, dipping the baked product in an alkoxide containing titanium, and sintering the alkoxide-covered baked product in a nitrogen gas atmosphere. The sintered product has very hard titanium carbide, nitride or carbide-nitride particles deposited on the base metal surface. The particles are partly embedded in the base metal and partly protrude from its surface, and are, therefore, very unlikely to come off, while they withstand a temperature change very well.

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 debonding layer is formed on fibers such as silicon carbide fibers by fing a thin film of a metal such as nickel or iron on the silicon carbide fibers and then annealing at a temperature of about 350-550.degree. C. to form a debond layer of a metal silicide and carbon. These fibers having the debond coating can be added to composite forming materials and the mixture treated to form a consolidated composite. A one heating-step method to form a consolidated composite involves inserting the silicon carbide fibers with just the initial metal film coating into the composite forming materials and then heating the mixture to form the debond coating in situ on the fibers and to form the consolidated composite. Preferred heating techniques include high temperature annealing, hot-pressing, or hot isostatic pressing (HIP).

Abstract: A heat-resistant, thermally insulative, ductile port liner for a head of an internal combustion (IC) engine having a tube-shaped structure formed from at least one layer of fiber reinforced ceramic matrix composite (FRCMC) material. The FRCMC material includes a polymer-derived ceramic resin in its ceramic form and fibers. In a first embodiment of the port liner, the tube-shaped structure has one FRCMC layer forming the sole, solid wall of the structure. Whereas, in a second embodiment, the tube-shaped structure has two FRCMC layers forming inner and outer walls of the structure, respectively, with an intervening space separating the inner and outer walls. The intervening space is sealed at both ends. It can be filled with a thermally insulating material, evacuated and held at substantially a vacuum pressure, or filled with a gas. Once the port liner has been formed, it is preferably cast-in-place when the metal head of the IC engine is formed.

Abstract: Small diameter silicon carbide-containing fibers are provided in a bundle such as a fiber tow that can be formed into a structure where the radii of curvature is not limited to 10-20 inches. An aspect of this invention is directed to impregnating the bundles of fibers with the slurry composition to substantially coat the outside surface of an individual fiber within the bundle and to form a complex shaped preform with a mass of continuous fibers.

Abstract: A wafer employing a silicon carbide sintered body is provided. The density of the silicon carbide sintered body is 2.9 g/cm.sup.3 or more. The silicon carbide sintered body is obtained by sintering a mixture in which silicon carbide powder and a non-metal-based sintering additive are mixed uniformly. The non-metal-based sintering additive is formed of an organic compound which generates carbon upon heating or the like. As a result, a wafer with excellent heat resistance and acid resistance and which causes little contamination is provided.

Abstract: Structural ceramic matrix composite material to be employed as automotive engine parts and the like is provided with erosion-resistant qualities in several ways. For one, an erosion-resistant material is applied to the surface as by plasma spraying. The erosion-resistant material can also be mixed with the fibers of the material, particularly near the surface.

Abstract: A heat-resistant, thermally insulative, ductile port liner for a head of an internal combustion (IC) engine having a tube-shaped structure formed from at least one layer of fiber reinforced ceramic matrix composite (FRCMC) material. The FRCMC material includes a polymer-derived ceramic resin in its ceramic form and fibers. In a first embodiment of the port liner, the tube-shaped structure has one FRCMC layer forming the sole, solid wall of the structure. Whereas, in a second embodiment, the tube-shaped structure has two FRCMC layers forming inner and outer walls of the structure, respectively, with an intervening space separating the inner and outer walls. The intervening space is sealed at both ends. It can be filled with a thermally insulating material, evacuated and held at substantially a vacuum pressure, or filled with a gas. Once the port liner has been formed, it is preferably cast-in-place when the metal head of the IC engine is formed.

Abstract: Ceramic structure having therein reinforcing fibers and backfilled strands s prepared by the arranging tows of fugitive and reinforcing fibers parallel to each other to form a fiber preform, contacting the preform with a matrix precursor whereby the precursor deposits around the fibers, removing the preform from the precursor wherein the fibers are coated with the precursor, drying the preform to solidify the precursor on the fibers and to convert the precursor to a matrix form, calcining the preform to convert the matrix form on the fibers to another matrix form, removing the fugitive fibers from the preform to form channels therein, backfilling the channels with a material, and hot pressing the preform for densification purposes to form the ceramic structure containing spaced fibers and spaced backfilled material strands disposed in the matrix.

Abstract: The present invention relates to a method for the formation of amorphous boron silicon oxycarbide fibers and crystalline boron-doped silicon carbide fibers comprising: preparing a blend of a siloxane resin and a boron-containing polymer, forming the blend into green fibers, and then curing and pyrolyzing the fibers.

Abstract: A method of making a shaped article and composite therefor which comprises of a shaped tool, such as a mold and providing a composite of a quartz fabric disposed within a resin taken from the class consisting of inorganic silicon-based polymers, preferably polycarbosilanes having predominantly hydrogen and/or methyl groupings attached thereto and polysilanes having hydrogen and/or methyl grouping attached thereto, polycarbosilazanes, polyborosilazanes, polyborosilanes and certain polysiloxanes with attached groupings as noted for the similar materials as set forth above, which is moldable at a temperature below the curing temperature of the resin and cured by catalyst. The resin can be optionally filled with particulate material. A compaction pressure is applied to the composite to insure contact of the composite and the tool and prevent loss of less reactive resin components. The composite is then cured to hardness by increasing the temperature applied to the composite at a rate of about 10.degree. C.

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: The invention relates to new amorphous, high-strength SiBN(C) fibres which are at the same time resistant to high-temperature creep, their production and use.The fibres have a strength at room temperature of >2.5 GPa, a modulus of elasticity of >250 GPa and a creep value m of from 0.4 to 1 (in accordance with standard BSR test, 1 hour, 1400.degree. C.).

Abstract: Methods of making fiber reinforced ceramic matrix composite (FRCMC) parts by compression and injection molding. The compression molding method generally includes the initial steps of placing a quantity of bulk molding compound into a female die of a mold, and pressing a male die of the mold onto the female die so as to displace the bulk molding compound throughout a cavity formed between the female and male dies, so as to form the part. The injection molding method general includes an initial step of injecting a quantity of bulk molding compound into a cavity of a mold. In both methods, the bulk molding compound is a mixture which includes pre-ceramic resin, fibers, and, if desired, filler materials. Once the part has been formed by either method, the mold is heated at a temperature and for a time associated with the pre-ceramic resin which polymerizes the resin to form a fiber-reinforced polymer composite structure.

Abstract: An electrode for an electric double layer capacitor in which resin is used as a starting material and the manufacturing cost is low and a method of manufacturing the same are disclosed. A method of manufacturing an electrode for an electric double layer capacitor containing carbonized resin includes heating resin at a temperature equal to or higher than the temperature for finishing endothermic reaction of the resin upon melting (softening to be fluidized) of the resin and equal to or lower than the temperature for starting oxidizing reaction in an atmosphere of a pressure range of 0.

Abstract: A structural fiber reinforced ceramic matrix composite (FRCMC) material adapted for clutch use. The entirety of the frictional components of a clutch mechanism or only particular components thereof can be made of the FRCMC material. One embodiment has integrally molded fiber reinforced ceramic matrix composite clutch friction pads forming the friction surfaces of metal clutch parts. Clutch components exhibiting a higher temperature and wear-resistance than currently available clutch parts are described. These clutch components and pads exhibit improved performance at high temperatures and are highly wear-resistant in comparison to current clutch components.

Abstract: Ceramic matrix composites (CMC) of high density, preferably of the type SiC/SiC, are provided by a production process based on the infiltration of ceramic fiber cloths with a polymeric precursor solution containing, as fillers, inert powders having size much lower than the mean distance among the ceramic fibers which are used as basic material for the manufacturing of CMC, typically a nanometric granulometry. Such step is followed by the steps of hardening the cloths, pyrolysis of the polymer and repeated thickenings until the desired density is reached. A possible alternative process comprises a brief (<24 hours) treatment of infiltration of SiC from the vapor phase (CVI) with precursors and typical operative parameters for the deposition of silicon carbide followed by the repeated thickenings.

Abstract: Boron nitride articles are made by heat treating turbostratic BN powder to reduce its oxygen content to 5-8% (mesographitic BN), washing this heat-treated powder, mixing it with 5-8% amorphous boron, shaping the mixture, explosively compacting the shape by a hydrodynamic method and reaction sintering the compacted shape, to form the article.The article is then buried in a powder mixture of BN and SiC and heat treated, to getter residual B.sub.2 O.sub.3.After this, the article is impregnated with low-viscosity oligomers (MW<1000) of methylsilanes selected to yield a high proportion of SiC on pyrolysis, and the article is heat-treated to fill the pores evenly throughout its thickness with SiC.

Abstract: The present invention relates to a method for preparing a ceramic fiber from alkenyl or alkynyl functional resins and to the ceramic fibers produced therefrom. The method comprises (A) forming a fiber from a siloxane resin comprised of R.sup.1.sub.a R.sup.2.sub.b RSiO.sub.(3-a-b)/2 units wherein R is an unsaturated carbon group; each R.sup.1 is selected from the group consisting essentially of an aryl group having from 6 to 10 carbon atoms and functional derivatives thereof; each R.sup.2 is selected from the group consisting essentially of an alkyl group having from 1 to 4 carbon atoms and functional derivatives thereof; a has a value of 0, 1 or 2; b has a value of 0, 1, or 2 with the proviso that a+b <2; (B) curing the fiber by exposing the fiber to high energy radiation to render it non-fusible; and (C) heating the non-fusible fiber in an inert environment to a temperature above about 800.degree. C. to convert it to a ceramic fiber.

Abstract: The present invention relates to a method for preparing a ceramic fiber wherein the method comprises (A) forming a green fiber from an alk-1-enyl ether functional siloxane resin of the general formula (R.sup.1 SiO.sub.3/2).sub.q (R.sup.2 SiO.sub.3/2).sub.r (R.sup.1.sub.w R.sup.2.sub.x RSiO.sub.(3-w-x)/2).sub.s (R.sup.1.sub.w R.sup.2.sub.x R.sup.3 SiO.sub.(3-w-x)/2).sub.t wherein R is an alk-1-enyl ether group; each R.sup.1 is selected from an aryl group having from 6 to 10 carbon atoms; each R.sup.2 is selected from an alkyl group having from 1 to 4 carbon atoms; R.sup.3 is an alkenyl group having from 2 to 10 carbon atoms; w has a value of 0, 1 or 2; x has a value of 0, 1, or 2 with the provisio that w+x.ltoreq.2; q has a value of 0 to 0.98; r has a value of 0 to 0.98; s is greater than zero; t.gtoreq.0; s+t=0.02 to 0.5 and q+r+s+t=1; (B) curing the green fiber to render it non-fusible; and (C) heating the non-fusible fiber in an inert environment to a temperature above 800.degree. C.

Abstract: A method of preparing polymer derived silicon fibers comprising the steps of providing a spin dope solution comprising a silicon carbide forming organosilicon polymer, preferably polycarbosilane, a solvent, a soluble boron precursor, preferably solid boron hydride, and a nitrogen containing precursor, preferably polyvinylsilazane; spinning the solution to form high strength green fibers; and heat treating the green fibers to produce high strength, homogeneously doped, boron containing fibers. The fibers produced are high strength, homogeneously boron doped silicon carbide fibers with average tensile strength in the range of from about 2.0 to 4.0 GPa at room temperature.

Abstract: A ceramic fiber is made by spinning a plurality of polymeric materials each including at least one ceramic precursor into a composite fiber, and then pyrolysing the composite fiber to form a composite ceramic fiber of non-homogeneous composition. A preferred ceramic material for use in this method is made by pyrolysing an organo-metallic compound dispersed in an organic polymer carrier. The principal products are tailored matrix-compatible ceramic fibers for reinforcements, and have a core-sheath structure made by coaxial spinning methods. A core of desired mechanical properties, such as silicon carbide, is given a chemically appropriate surface layer. Transition metals compounds are preferred, in a range of organo-metallic ceramic precursors that include carborane derivatives. Allowed additives include metal-silicon compounds, other ceramics, corresponding metal oxides and elementary metals.

Abstract: Methods of making fiber reinforced ceramic matrix composite (FRCMC) parts by compression and injection molding. The compression molding method generally includes the initial steps of placing a quantity of bulk molding compound into a female die of a mold, and pressing a male die of the mold onto the female die so as to displace the bulk molding compound throughout a cavity formed between the female and male dies, so as to form the part. The injection molding method general includes an initial step of injecting a quantity of bulk molding compound into a cavity of a mold. In both methods, the bulk molding compound is a mixture which includes pre-ceramic resin, fibers, and, if desired, filler materials. Once the part has been formed by either method, the mold is heated at a temperature and for a time associated with the pre-ceramic resin which polymerizes the resin to form a fiber-reinforced polymer composite structure.

Abstract: Disclosed are novel ceramic matrix composites in which coated refractory fibers are imbedded in a ceramic matrix derived from a modified hydrogen silsesquioxane resin.

Abstract: Fiber reinforced ceramic matrix composites are prepared by coating refractory fibers having a interfacial coating thereon with a curable preceramic polymer having a char which contains greater than about 50% sealant oxide atoms followed by forming the coated fibers into the desired shape, curing the coated fibers to form a pre-preg, heating the pre-preg to form a composite and heating the composite in an oxidizing environment to form an in situ sealant oxide coating on the composite. The resultant composites have good oxidation resistance at high temperature as well as good strength and toughness.

Abstract: The invention pertains to a composite ceramic fibre which is made from a self-supporting composite polymeric fibre by the conjugate spinning of at least two dissimilar pre-ceramic polymers in shapes varying from cylindrical to ribbon-like, and pyrolysing the spun fibre to form a composite bilateral, core sheath or matrix-fibril ceramic fibre having regions with ceramic compositions derived from each of the polymers, enabling physical and chemical characteristics to be widely varied for use as matrix reinforcements and other applications. A pyrolysis furnace includes countercurrent controlled atmosphere gas flow for chemically stabilizing or modifying the fibres.

Abstract: Disclosed is a method for the preparation of a fiber-reinforced silicon carbide-based composite ceramic body having outstandingly high mechanical strengths even without using any sintering aids or without undertaking the hot-press sintering method. The method comprises impregnating carbon fibers or silicon carbide fibers with a slurry containing an elementary silicon powder, an organic resin, e.g., phenolic resins, and an organosilicon polymer, e.g., polysilastyrenes, according to a specified formulation and shaping the impregnated fibers into a green body which is subjected to a calcination treatment at 1300.degree.-1500.degree. C. in an inert atmosphere under normal pressure.