Abstract: A heat dissipation sheet includes a first sheet composed of a plurality of first carbon nanotubes, and a second sheet composed of a plurality of second carbon nanotubes, wherein the first sheet and the second sheet are coupled in a stacked state, and the first carbon nanotubes and the second carbon nanotubes are different in an amount of deformation when pressure is applied.

Abstract: A method for manufacturing items by the selective fusion of polymer powder layers, particularly rapid prototyping by solid phase sintering a thermoplastic polymer powder by means of a laser, having characteristics of grading and particle distribution is described. Items obtained from such a method are also described.

Abstract: Methods of producing silicon carbide fibers. The method comprises reacting a continuous carbon fiber material and a silicon-containing gas in a reaction chamber at a temperature ranging from approximately 1500° C. to approximately 2000° C. A partial pressure of oxygen in the reaction chamber is maintained at less than approximately 1.01×102 Pascal to produce continuous alpha silicon carbide fibers. Continuous alpha silicon carbide fibers and articles formed from the continuous alpha silicon carbide fibers are also disclosed.

Abstract: Hardness, ageing resistance, wetting behavior in relating to water and high thermal conductivity are known characteristics of sintered molded bodies consisting of aluminum oxide; high strength and a high resistance to cracking, i.e., damage tolerance are known characteristics of sintered molded bodies consisting of zirconium oxide. These properties are combined in a material having a large fraction of aluminum oxide, zirconium oxide and optionally strontium aluminate.

Abstract: A material composed of a large fraction of aluminum oxide, zirconium oxide and strontium aluminate.

Abstract: A superhard element (22) for a machine tool, comprising polycrystalline cubic boron nitride (PCBN) material containing whiskers of a ceramic material, the PCBN material comprising at least about 50 volume percent cubic boron nitride (cBN) material dispersed in a binder matrix comprising a compound including titanium and the whiskers; the content of the whiskers being at least 1 weight percent and at most 6 weight percent of the binder matrix.

Abstract: In a carbon-containing refractory composed of a refractory aggregate, a carbon based raw material, and a carbon bond connecting between the refractory aggregate or the carbon based raw material, transition metal-containing nanoparticles having particle diameters of 1,000 nm or less and containing a transition metal are contained in the above-described carbon bond while being dispersed. When the carbon-containing refractory is heat-treated, flexible structures of carbon fiber-shaped textures having diameters of 50 nm or less are formed in the inside of a carbon bond and, thereby, an increase in strength, a reduction in modulus of elasticity, and a reduction in thermal expansion coefficient are facilitated. Therefore, a carbon-containing refractory exhibiting high thermal shock resistance, high abrasion resistance, and high corrosion resistance are provided.

Abstract: A composition of matter comprising 0.01 to 35% by weight of Al2O3, having a length of 10-20 ?m and a surface altered by wet etching, 0.01 to 98% by weight of SiC, having a length of 10-20 ?m and a surface altered by dry etching; and 0.01-15% by weight of kaolin, altered by treatment with Na2SiF6, with the above constituents being blended into a SiC/Al2O3 composite. Alternative embodiments are methods of producing the compositions described above. Further embodiments include products made by the process described above.

Abstract: Composite materials composed of cubic boron nitride (cBN) and a matrix component of various ceramic oxides, nitrides, and solid solutions of matrix materials as well as whisker reinforcements. Methods of manufacture and their use in high performance machining of ferrous metals are also claimed and disclosed.

Abstract: A method of sintering a ZrB2—SiC composite body at ambient pressures, including blending a first predetermined amount of ZrB2 powder with a second predetermined amount of SiC powder, wherein both powders are characterized by the presence of surface oxide impurities. Next the blended powders are mixed to yield a substantially homogeneous powder mixture and a portion of the substantially homogeneous powder mixture is formed into a green body. The body is fired to a first temperature, wherein substantially all surface oxide impurities are reduced and/or volatilized to substantially eliminate oxides from the green body, and the body is heated to a second temperature and sintered to yield a composite body of at least about 99 percent theoretical density (more typically at least about 99.5 percent theoretical density) and characterized by SiC whisker-like inclusions distributed substantially evenly in a ZrB2 matrix.

Abstract: Boron carbide ceramics produced by spark sintering methods have more desirable mechanical properties than conventionally produced carbides. The boron carbide ceramics include amorphous boron, amorphous carbon, and Al2O3 powder as a sintering aid. The boron carbides may also contain a carbon nano fiber in a nearly homogeneously dispersed state. The sintered compact has a relative density of a boron carbide ceramic of approximately not less than 99%. The boron carbide ceramics are prepared preferably by subjecting a mixed powder of the starting raw materials and the carbon nano fiber to simultaneous synthesis and sintering using the spark plasma sintering method.

Abstract: A needle-shaped ceramic body having as its base material a cordierite porous body having a high specific surface area and superior thermal shock resistance, and a needle-shaped catalyst-ceramic body are provided. The present invention relates to a needle-shaped ceramic body having as its base material a needle-shaped cordierite in which the tips thereof are rounded, a needle-shaped catalyst-ceramic body loaded with a catalyst, and a method of production of a ceramic body in which a portion of a raw material (fluoride) gasified by a reaction between raw materials is grown into a needle like shape on the metal catalyst (Fe), wherein the tips of needle-shaped particles are rounded, using a vapor-liquid-solid (VLS) reaction, in a raw material burning process.

Abstract: Boron carbide ceramics produced by spark sintering methods have more desirable mechanical properties than conventionally produced carbides. The boron carbide ceramics include amorphous boron, amorphous carbon, and Al2O3 powder as a sintering aid. The boron carbides may also contain a carbon nano fiber in a nearly homogeneously dispersed state. The sintered compact has a relative density of a boron carbide ceramic of approximately not less than 99%. The boron carbide ceramics are prepared preferably by subjecting a mixed powder of the starting raw materials and the carbon nano fiber to simultaneous synthesis and sintering using the spark plasma sintering method.

Abstract: A method of sintering a ZrB2—SiC composite body at ambient pressures, including blending a first predetermined amount of ZrB2 powder with a second predetermined amount of SiC powder, wherein both powders are characterized by the presence of surface oxide impurities. Next the blended powders are mixed to yield a substantially homogeneous powder mixture and a portion of the substantially homogeneous powder mixture is formed into a green body. The body is fired to a first temperature, wherein substantially all surface oxide impurities are reduced and/or volatilized to substantially eliminate oxides from the green body, and the body is heated to a second temperature and sintered to yield a composite body of at least about 99 percent theoretical density and characterized by SiC whisker-like inclusions distributed substantially evenly in a ZrB2 matrix.

Abstract: Composite materials composed of cubic boron nitride (cBN) and a matrix component of various ceramic oxides, nitrides, and solid solutions of matrix materials as well as whisker reinforcements. Methods of manufacture and their use in high performance machining of ferrous metals are also claimed and disclosed.

Abstract: A nanostructured monolithic titanium boride (TiB) material and methods of forming such a material are disclosed and described. This material has a room-temperature four-point flexural strength about three times that of commercially available titanium diboride (TiB2). The achievement of nanostructured internal microstructural arrangement having a network of interconnected titanium monoboride whiskers affords a very high strength to this material above some of the best ceramic materials available in the market. The material contains a small amount of titanium and a densifier, but it is largely made of TiB phase with substantially no TiB2. The nanostructured monolithic titanium boride material can be formed by high temperature processing of a powder precursor having carefully selected weight and size distributions of titanium powder, titanium diboride powder, and densifier powder.

Abstract: A nanostructured monolithic titanium boride (TiB) material and methods of forming such a material are disclosed and described. This material has a room-temperature four-point flexural strength about three times that of commercially available titanium diboride (TiB2). The achievement of nanostructured internal microstructural arrangement having a network of interconnected titanium monoboride whiskers affords a very high strength to this material above some of the best ceramic materials available in the market. The material contains a small amount of titanium, but it is largely made of TiB phase with substantially no TiB2. The nanostructured monolithic titanium boride material can be formed by high temperature processing of a powder precursor having carefully selected weight and size distributions of titanium and titanium diboride powders. Potential applications of this material can include wear resistant components such as die inserts for extrusion dies, nozzles, armor, electrodes for metal refining etc.

Abstract: A ceramic matrix composite material is disclosed having non-oxide ceramic fibers, which are formed in a complex fiber architecture by conventional textile processes; a thin mechanically weak interphase material, which is coated on the fibers; and a non-oxide or oxide ceramic matrix, which is formed within the interstices of the interphase-coated fiber architecture. During composite fabrication or post treatment, the interphase is allowed to debond from the matrix while still adhering to the fibers, thereby providing enhanced oxidative durability and damage tolerance to the fibers and the composite material.

Abstract: A ceramic body, as well as a method for making the same, wherein the ceramic body contains aluminum oxynitride and whiskers, (and optionally) one or more of titanium carbonitride, and/or alumina, and/or zirconia, and/or other component(s).

Abstract: A method of sintering a ZrB2—SiC composite body at ambient pressures, including blending a first predetermined amount of ZrB2 powder with a second predetermined amount of SiC powder, wherein both powders are characterized by the presence of surface oxide impurities. Next the blended powders are mixed to yield a substantially homogeneous powder mixture and a portion of the substantially homogeneous powder mixture is formed into a green body. The body is fired to a first temperature, wherein substantially all surface oxide impurities are reduced and/or volatilized to substantially eliminate oxides from the green body, and the body is heated to a second temperature and sintered to yield a composite body of at least about 99 percent theoretical density and characterized by SiC whisker-like inclusions distributed substantially evenly in a ZrB2 matrix.

Abstract: A ceramic body, as well as a method for making the same, wherein the ceramic body contains aluminum oxynitride and whiskers, (and optionally) one or more of titanium carbonitride, and/or alumina, and/or zirconia, and/or other component(s).

Abstract: The present invention relates to thermally conductive, elastomeric pads. The pads can be made by injection-molding a thermally conductive composition comprising about 30 to 60% by volume of an elastomer polymer matrix and about 25 to 60% by volume of a thermally conductive filler material. The resultant pads have heat transfer properties and can be used as a thermal interface to protect heat-generating electronic devices.

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: An improved cutting tool insert and a method for the preparation of such cutting tool insert, having a sintered alumina and silicon carbide whisker composite material body, comprising the steps of milling and mixing the powdered starting materials of said composite material and forming said material into a preformed workpiece, heating up said workpiece at a heating rate of from about 20 to about 60° C. per minute to a sintering temperature of between from about 1600 to about 2300° C., and holding at said sintering temperature for a holding time of from about 5 to about 60 minutes at a pressure of between from about 20 to about 100 MPa.

Abstract: An inorganic polymeric aluminosilicate material and a method for preparing the same, are disclosed. Instead of having a fibrous structure, the material has a structure consisting of spindles with a length in the range of from 10 to 100 &mgr;m and a width in the range of from 2 to 20 &mgr;m. This polymeric alumino-silicate can be used for the production of antistatic layers.

Abstract: A ceramic composite made by compacting a starting powder blend. The composite includes between about 50 volume percent and about 99 volume percent of a ceramic matrix; and between about 1 volume percent and about 50 volume percent as-processed silicon carbide whiskers. The ceramic composite having a fracture toughness (KIC) of greater than about 4.0 MPam1/2. The ceramic has a silicon carbide whisker density as measured in whiskers per square millimeter equal to or less than about 1500 times the volume percent of silicon carbide whiskers, but in a density sufficient for the ceramic composite to have the fracture toughness.

Abstract: A reinforcing material is uniformly dispersed in a yttrium aluminum garnet matrix material for use as a machine tool material specially suited for machining Ti or a Ti alloy. The matrix material and the reinforcing material are present in proportions selected such that the machine tool material is substantially resistant to transfer of impurities to a Ti or Ti alloy by way of either chemical reaction with or diffusion into the Ti or Ti alloy material to be machined. The matrix material preferably comprises Y3Al5O12. The reinforcing material may comprise SiCw, TiC, TiN, TiB2, or combinations thereof and is preferably present in an amount sufficient to enable electrical discharge machining of the machine tool material. In addition, the machine tool material defines a thermodynamically stable phase at relatively high machining temperatures.

Abstract: The present invention relates to high temperature composite materials formed from nano-sized powders suitable for use in the manufacture of jet engine components. The composite materials consist essentially of a matrix formed from a powdered material having a particle size in the range of from about 1 to about 100 nanometers and a plurality of reinforcing fibers embedded within the matrix and comprising from about 20% to about 40% by volume of the composite material. The method of manufacturing the composite materials broadly comprises the steps of mixing the powdered material with the reinforcing fibers and consolidating the mixture to form the composite material.

Abstract: A mullite composition is comprised substantially of mullite grains that are essentially chemically bound wherein the composition has at least two adjoining regions that have substantially different microstructures. The composition may be produced by forming a mixture of one or more precursor compounds having the elements present in mullite; shaping the mixture into a porous green shape applying a nucleation control agent to a portion of the porous green shape and then heating the porous green shape under an atmosphere and to a temperature sufficient to form the mullite composition.

Abstract: Rare-earth alloy is cast into a sheet (6) or the like by using a tundish (3, 13). The refractory material of the tundish used for casting does not necessitate preheating for improving the flowability of the melt (2). The refractory material used essentially consists of 70 wt % or more of Al2O3 and 30 wt % or less of SiO2, or 70 wt % or more of ZrO2 and 30 wt % or less of one or more of Y2O3, Ce2O3, CaO, MgO, Al2O3, TiO2 and SiO2. The refractory material has 1 g/cm3 or less of bulk density, has 0.5 kca/(mh° C.) or less of thermal conductivity in the temperature range of from 1200 to 1400° C., and has 0.5 wt % or less of ratio of ignition weight-loss under the heating condition of 1400° C. for 1 hour.

Abstract: A composite ceramic-metal material has an Al2O3 matrix interpenetrated by a network of a ductile metal phase with a higher meltin temperature than aluminum and which makes up 15 to 80 vol. % of its total volume. The Al2O3 matrix forms a coherent network that makes up 20 to 85 vol. %, and the material contains 0.1 to 20 atom % aluminide. To produce this composite material, a green body shaped by powder metallurgy and which contains a finely divided powdery mixture of Al2O3 and optionally other ceramic substances, as well as one or several metals or metal alloys different from aluminum and to which 0.1 to 20 atom % aluminum are added, in relation to the metal proportion, is sintered. The composition is selected in such a way that maximum 15 vol. % aluminide phase can be formed in the finished sintered body.

Abstract: A method of producing alumina-silica ceramic with mullite whisker structure has been produced as armor materials for protecting high velocity projectile. The mixing composition of starting powders consists of alumina, quartz, kaoline, feldspar and talc, and the green compacts were sintered at the temperature range from 1200 to 1450° C. for 0.5 to 3 hours. Mullite whisker structure in the ceramic was fabricated and grown in the period of liquid phase sintering. The whisker phase of mullite is homogeneously distributed in the ceramic.

Abstract: A sensor material for measuring physical parameters capable of configuring a sensor capable of directly measuring a high value of physical parameters such as high stress or high pressure without employing a pressure resistance container. The sensor material for measuring static and dynamic physical parameters includes a matrix made of an electrically insulating ceramic material, and piezoresistance materials which are dispersed in the matrix so as to be electrically continuous to each other.

Abstract: The present invention relates to thermally conductive, elastomeric pads and methods for manufacturing such pads. The methods involve injection-molding a thermally conductive composition comprising about 30 to 60% by volume of an elastomer polymer matrix and about 25 to 60% by volume of a thermally conductive filler material. The resultant pads have heat transfer properties and can be used as a thermal interface to protect heat-generating electronic devices.

Abstract: A method of producing alumina-silica ceramic with mullite whisker structure has been produced as armor materials for protecting high velocity projectile. The mixing composition of starting powders consists of alumina, quartz, kaoline, feldspar and talc, and the green compacts were sintered at the temperature range from 1200 to 1450° C. for 0.5 to 3 hours. Mullite whisker structure in the ceramic was fabricated and grown in the period of liquid phase sintering. The whisker phase of mullite is homogeneously distributed in the ceramic.

Abstract: A filter media structure, which is capable of operating in the micro- and nanofiltration regime, offers: low cost, durability, high temperature and chemical resistance, high permeability, high flow rate, low pressure drop across the filter media, high mechanical strength, separation efficiency, and biocompatibility. The filter media structure is comprised of mixture of carbon or ceramic fibers and inorganic fiber whiskers generally having a diameter of from about 0.03 to about 5 microns. The present invention further provides a method of preparing a filter media structure comprising mixing together a) inorganic fibers; b) inorganic fiber whiskers; c) a water soluble binder, and optionally depositing a thin layer of pyrolytic carbon on the surface of the inorganic fibers and inorganic fiber whiskers comprising the filter media structure. The filter media structure is selected from the group consisting of a paper, felt and fabric.

Abstract: A MoSi2 pest resistant material includes in-situ grown &bgr;-Si3N4 whiskers. In addition to excellent pest resistance, the material provides a lower coefficient of thermal expansion for better match with continuous reinforcing fibers such as SiC fibers. A two stage heating and pressing production technique enables lower temperature processing with substantially full densification.

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 hydrothermal method for forming nanoparticles of a rare earth element, oxygen and fluorine has been discovered. Nanoparticles comprising a rare earth element, oxygen and fluorine are also described. These nanoparticles can exhibit excellent refractory properties as well as remarkable stability in hydrothermal conditions. The nanoparticles can exhibit excellent properties for numerous applications including fiber reinforcement of ceramic composites, catalyst supports, and corrosion resistant coatings for high-temperature aqueous solutions.

Abstract: A composition and method of fabricating pressureless sintered 70 volume % silicon nitride—30 volume % barium aluminum silicate ceramic composites. The composites are made from 70 volume % silicon nitride, containing varying amounts and size distributions of initial &bgr;-silicon nitride, and 30 volume % barium aluminum silicate. The resulting ceramic composites contain microstructures with coarse &bgr;-silicon nitride whiskers, as well as narrow distributions of short &bgr;-silicon nitride whiskers, surrounded by fine barium aluminum silicate grains. The resulting composites exhibit improved fracture toughness and flexural strength.

Abstract: A MoSi2 pest resistant material includes in-situ grown &bgr;-Si3N4 whiskers. In addition to excellent pest resistance, the material provides a lower coefficient of thermal expansion for better match with continuous reinforcing fibers such as SiC fibers. A two stage heating and pressing production technique enables lower temperature processing with substantially full densification.

Abstract: A filter media system, which is capable of operating in the microfiltration regime, offers: low cost, durability, high temperature and chemical resistance, no particulation, mechanical strength, separation efficiency, and biocompatibility. A filter media system is comprised of a carbon or ceramic composite substrate which contains a carbon or ceramic matrix reinforced with carbon or ceramic fibers. The composite has an array of carbon or ceramic fiber whiskers grown onto its surface or in its bulk. A process is provided for manufacturing the filter media system wherein a carbon fiber is disposed in a matrix deposited by a CVI or LPI process, at temperatures of about 900 to about 1200° C. to achieve a weight gain of about 10 to 200% (the ceramic matrix is deposited by a CVI process from an aqueous slurry or by use of a preceramic polymer). This composite is treated with an aqueous solution of metal catalyst salt and is then heated in hydrogen at elevated temperatures to reduce the metal salt to metal.

Abstract: A ceramic composition produced by the consolidation of a blend of starting components. The composition comprises a matrix with one or more of the carbides, nitrides and carbonitrides of hafnium, molybdenum, zirconium, tantalum, niobium, vanadium and tungsten, titanium nitride, and titanium carbonitride in an amount that is greater than 50 volume percent of the matrix. The matrix comprises between 60 and 99.8 volume percent of the composition. Ceramic whiskers are uniformly dispersed throughout the matrix wherein the ceramic whiskers comprises between 0.2 and 40 volume percent of the composition.

Abstract: A composition and method of fabricating pressureless sintered 70 volume % silicon nitride-30 volume % barium aluminum silicate ceramic composites. The composites are made from 70 volume % silicon nitride, containing varying amounts and size distributions of initial &bgr;-silicon nitride, and 30 volume % barium aluminum silicate. The resulting ceramic composites contain microstructures with coarse &bgr;-silicon nitride whiskers, as well as narrow distributions of short &bgr;-silicon nitride whiskers, surrounded by fine barium aluminum silicate grains. The resulting composites exhibit improved fracture toughness and flexural strength.

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.