Abstract: A method of manufacturing a ceramic matrix composite comprises forming a slurry comprising a ceramic sol, filler particles and a solvent and forming laminates of fibres (12). The laminates of fibres (12) are impregnated with the slurry and are stacked (14) on a mould (10). The stack (14) of laminates of fibres (12) is covered by a porous membrane (16), a breather fabric (18) and a vacuum bag (20). The vacuum bag (20) is evacuated and is heated to a temperature of 60° C. for 10 hours to produce a ceramic matrix composite. The ceramic matrix composite is then heated to a temperature of 1200° C. at atmospheric pressure to sinter the ceramic matrix composite.

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: An asbestos free, calcium silicate insulating material suitable for use in the casting of molten non-ferrous metals, and suitable for use in applications where a fire resistant, heat insulating, electrical insulating, and corrosion resistant material is desirable. The calcium silicate insulating material is produced by combining lime, a siliceous component, alumina silica microspheres, wollastonite and organic fibrous material in the presence of water to form a slurry. The slurry is then placed under steam pressure, to react the lime, siliceous component and water, dried, and heat treated if necessary.

Abstract: A process for making a heat treated ground ceramic cutting tool and the resultant cutting tool. The process comprising the steps of: providing an uncoated ground ceramic cutting tool having at least a portion thereof ground; and heat treating the uncoated ground ceramic cutting tool so as to form the heat treated ground ceramic cutting tool.

Abstract: Ceramic oxide pre-forms comprising substantially continuous, alpha alumina fibers, and methods for making the same. The ceramic oxide pre-forms are useful, for example, as in making metal matrix composites reinforced with substantially continuous, alpha alumina fibers.

Abstract: Carbon fiber bundles may be dispersed into substantially single mono-filaments in pitch by stirring a mixture of fibers and pitch at a temperature at which the pitch has a viscosity of about 0.1 to about 5 poise. The resulting fiber pitch binder contains about 0.5 to about 10.0 wt. % carbon fibers substantially dispersed as substantially single mono-filaments which are randomly oriented which may then be used directly as a binder for producing carbon bodies, for example, graphite electrodes, pinstock or specialty graphite articles. This unique binder using an economical amount of carbon fibers has the capacity to increase the strength and reduce the coefficients of thermal expansion of the resulting carbon products in more than one direction due to the random orientation of the carbon fibers.

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: The present invention relates to a sintered ceramic composite implant material and a fabrication method thereof. A sintered ceramic composite implant material includes an apatite matrix phase, a ceramic secondary phase located in the apatite matrix phase, a barrier layer coating the ceramic secondary phase. The secondary phase compensates for and improves the mechanical properties of the apatite matrix phase and the barrier layer restrains an interfacial reaction between the apatite matrix phase and the secondary phase.

Abstract: A shaped sintered fibrous porous body exhibits a structure with a three-dimensional corrugated or undulating shape and porosity.

Abstract: A microwave oven food container in the form of a receptacle for foodstuffs. The receptacle is composed of a polymeric material containing a microwave absorbent filler, which may comprise carbon or metal particles.

Abstract: A method for changing the dielectric properties of a polymer impregnated and pyrolyzed ceramic matrix composite (polymer impregnated and pyrolyzed ceramic matrix composite) is disclosed. The polymer impregnated and pyrolyzed ceramic matrix composite can be used in aircraft and turbine engines. polymer impregnated and pyrolyzed ceramic matrix composite comprises a ceramic matrix, a reinforcing fiber, and at least 1 additive used to change dielectric properties (dielectric constant and loss factor). The additive can be a low dielectric constant material having a dielectric constant in the range of 1 to 7.5. The low dielectric constant material can be an oxide such as silica or aluminosilicate or a non-oxide such as silicon nitride, boron nitride, or silicon carbide. The low dielectric constant material can be incorporated in the ceramic matrix as a filler.

Abstract: Carbon fiber-filled, thermoplastic resin compositions having improved electrical properties at a given level of carbon fibers are formed from thermoplastic resin and carbon fibers associated into bundles with a binder. The thermoplastic resin and the binder are selected to be incompatible such that the adhesion of the fiber to the resin is poor. An exemplary composition is formed from a thermoplastic polymer selected from among polystyrene, high impact polystyrene, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyphenylene ether, polyether imide and blends thereof; and carbon fibers associated into bundles with a polyamide terpolymer binder. The bundles are dispersed within the thermoplastic polymer. The compositions can be used for injection molding of articles for use as components in applications requiring static dissipation and/or EMI shielding. Such articles include electronic devices, dust handling equipment and notebook computer enclosures.

Abstract: Carbon fiber-filled PC-ABS resin compositions which have improved electrical properties at a given level of carbon fibers, and which do not suffer from as significant a decrease in impact strength as would result from the introduction of generic carbon fibers are achieved using carbon fibers treated with a polyamide terpolymer binder. The bundles are dispersed within the PC-ABS blend. The compositions can be used for injection molding of articles for use as components in applications requiring static dissipation and/or EMI shielding. Such articles include, but are not limited to electronic devices, dust handling equipment and notebook computer enclosures.

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 process for making a low volume fraction preform for a metal matrix composite including the steps of: mixing a reinforcement with a binder and sacrificial fillers to provide a castable slurry; placing the slurry in a mold to provide a green cast preform; drying the green casting to remove any water and/or solvent; firing the green preform at a relatively low temperature to burn off the sacrificial fillers; firing the green preform at an elevated temperature to sinter the binder to bond the reinforcement together. The firing steps include particular combinations of temperature and time to ensure decomposition of the sacrificial filler and sintering without destruction or cracking of the green preform.

Abstract: The present invention relates to a method for sintering of a silicon nitride based material using gas pressure sintering technique. It has been found that using a sintering atmosphere containing nitrogen and 0.1-10 vol-% carbon monoxide a cutting tool material is obtained with improved properties, particularly increased edge toughness, when machining heat resistant alloys.

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: A nuclear medical drug for localize radiotheraphy of a tumor and methods for its preparation. The drug includes a radioactive ceramic or glass particle having biocompatiblity. Ceramic or glass particles prepared by traditional processes become radioactive particles with pure .beta.-particle-emitting radionuclides after being irradiated with an appropriate flux of neutrons. The radioactive particle with suitable particle size can then be dispersed into a contrast medium for injection or can be implanted by operation.

Abstract: An internal combustion engine of either two-cycle or four-cycle construction including a block having at least one cylinder bore therein having sidewalls carrying a liner of a structural fiber reinforced ceramic matrix composite material disposed in sealed fiber reinforced sliding relationship within the cylinder bore, and a cylinder head sealing atop end of the cylinder bore to form a closed combustion chamber in combination with the piston. The cylinder head also has the structural fiber reinforced ceramic matrix composite material disposed on an inner surface thereof facing the combustion chamber. The preferred engine is a two-cycle engine having an externally scavenged intake system and an oil sump lubricating system thereby eliminating the need to separately mix or inject lubricating oil. Higher operating temperatures and closer tolerances allow higher fuel efficiency and less pollutant production.

Abstract: A process for manufacturing a ceramic metal composite body in the case of which a dimensionally stable and porous sacrificial body is produced from ceramic initial products and is filled at a filling temperature with a softened metal, particularly under an increased pressure. The filled sacrificial body is heated to a reaction temperature and the metal to be filled in, BMe, is reacted with a metal of the ceramics. KMe, forming the ceramic metal composite body which has a ceramic phase having KMe.sub.m B.sub.x and/or KMe.sub.n C.sub.y and/or KMe.sub.o CN and BMe.sub.p O.sub.3 and has a metallic phase having an intermetallic compound which is formed of KMe and BMe, the filling temperature being lower than the reaction temperature and higher than or equal to the softening temperature of the metal.

Abstract: A method of unidirectionally aligning the whiskers during tape casting and a sintered silicon nitride laminate of controlled properties and microstructure through alignment of the reinforcing grains fabricated by using the method are disclosed. The whiskers are unidirectionally oriented by placing a row of guides 0.2-0.5 mm apart from each other at exit of the reservoir of the slip containing the whiskers during tape casting. The silicon nitride comprising 10-30 volume % of elongated large grains growing from the .beta.-Si.sub.3 N.sub.4 whiskers and oriented unidirectionally in the fine grained matrix is fully densified by gas pressure sintering at 1900.degree. C. It exhibits a fracture toughness value as high as 9.24 Mpa m normal to the whisker alignment according to the Evans-Charles' method disclosed in the Journal of the American Ceramic Society, 59 [7-8], 371-372 (1976).

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 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 composite ceramic board having a low dielectric constant and a low heat expansion coefficient and being suitable for use as a heat-resistant material having a high dimensional accuracy and a low dielectric constant, which is formed of a sintered substrate (II) having a thickness of 0.2 to 10 mm and a thermosetting resin (R) which is integrated into the sintered substrate (II) by being impregnated into pores of the sintered substrate (II) under vacuum and cured, the sintered substrate (II) being a substrate obtained from an inorganic continuous porous sintered body (I) produced by sintering a spherical inorganic powder having an average particle diameter of 0.1 to 10 .mu.m in the presence of a sintering aid, the sintered inorganic powder substantially retaining the spherical forms, the inorganic continuously porous sintered body (I) having an average pore diameter of 0.1 to 10 .mu.m, a true porosity of 8 to 35% and a closed porosity of 2% or less.

Abstract: An improved friction material may be made having reinforcing fibers aligned generally perpendicular to the friction surface of said material by forming a paper of fibrous friction materials such that the fibers in the paper are aligned closely to the longitudinal axis of the paper and then folding or cutting the paper into pleats or strips such that the pleats or strips are bonded together with the edges defining the friction surface of the friction body and the fibers perpendicular to that surface.

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: Ceramic structure and process for its preparation wherein the structure is omposed of a matrix having therein parallel and spaced reinforcing fibers and strands of backfilled ceramic material, the strands being parallel to the reinforcing fibers; and wherein the process includes the steps of 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 materi

Abstract: A method is now disclosed for the making of compressed refractory fiber shapes, e.g., compressed ceramic fiber shapes, having a textured surface and an aggregate body. The shapes can be obtained by molding and therefore may be simple or complex. For the process, small discrete fragments of refractory fiber in accumulated form are suspended in a colloidal dispersion, such as the colloidal dispersion provided by colloidal silica. Colloidal mixtures, as of colloidal silica with colloidal alumina are also most serviceable. The fragments and the dispersion are mildly mixed so as not to thoroughly disperse the fiber fragments, but rather to form globules of the fiber in the resulting blend. The resulting material is shaped, e.g., molded under pressure, and usually dried while under pressure, which drying can be at elevated temperature.

Abstract: An oxide ceramic composite suitable for fabricating components of combustion turbines and similar high temperature environments. The composite is fabricated by dispersing metal particles in a fiber preform and infiltrating the fiber preform with sol-gel matrix precursor material. Alternatively, the metal particles are mixed into the sol-gel matrix precursor material and the preform is infiltrated with the mixture. Later in the fabrication process, the metal particles oxidize and become oxidized metal when the sol-gel matrix precursor material is sintered. The oxidized metal has more volume and mass than the metal particles. As a result, the oxidized metal contributes to increasing the density of the composite so that it is suitable for use in combustion turbines and similar high temperature environments.

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: A ceramic matrix composite material comprising a matrix containing silicon carbide as the primary component and silicon nitride as the secondary component is disclosed. The silicon nitride includes not more than 1% by weight of iron and reinforcements mixed and dispersed. The ceramic matrix composite material is manufactured, for example, by forming a matrix containing reaction sintered silicon carbide as the primary component and nitriding the free metal silicon produced in the sintering process so that the free metal silicon will be converted to fine silicon nitride particles. Said metal silicon used for reaction sintering already contains iron. These processes enable the containing of a comparatively large amount of reinforcements, as well as the improvement of heat resistance of the sintered compact and the suppression of the deterioration of reinforcements.

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: A ceramic-forming prepreg tape is prepared by (a) dispersing in water a ceramic-forming powder and a fiber, (b) flocculating the dispersion by adding a cationic wet strength resin and an anionic polymer, (c) dewatering the flocculated dispersion to form a sheet, (d) wet pressing and drying the sheet, and (e) coating or impregnating the sheet with an adhesive selected from the group consisting of a polymeric ceramic precursor, and a dispersion of an organic binder and the materials used to form the sheet. The tape can be used to form laminates, which are then fired to consolidate the tapes to a ceramic.

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: 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.

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.