Abstract: A heat conductive aluminum nitride sintered body contains 100 parts by weight of aluminum nitride, at least 0.005 parts by weight and not more than 0.5 parts by weight of carbon, at least 0.01 parts by weight and not more than 15 parts by weight of a rare earth aluminum oxide in terms of the simple substance of a rare earth element, and at least 0.01 parts by weight and not more than 15 parts by weight of at least one element selected from a group of compounds containing elements belonging to the groups IVB, VB and VIB of the periodic table in terms of the simple substance of the element. Such a sintered body has a heat conductivity of at least 100 W/m.multidot.K. and not more than 270 W/m.multidot.K. at room temperature.

Abstract: Disclosed is a method of controlling the densification behavior of a metallic feature in a ceramic material, the method including the steps of:obtaining an unsintered ceramic material having at least one metallic feature therein;providing at least the metallic feature with a predetermined amount of carbonaceous material;heating the ceramic material and metallic feature to a predetermined temperature sufficient to cause sintering of the ceramic material, the metallic feature being at least partially inhibited from densifying at the predetermined temperature by the presence of the carbonaceous material.key aspect of the invention is subsequently removing with an oxidizing ambient some or, all of the carbonaceous residue at a predetermined temperature for the optimization of the physical characterization of the fired metallic component in ceramic material without adversely affecting distortion and alignment of the metallic feature.

Abstract: The inorganic foam body consists of an at least partially open-cell foam formed by thermally foaming and hardening a mixture comprising an alkali water glass and a filler from the group of aluminum oxide, silicon dioxide, aluminous cement, crushed rocks, graphite or mixtures thereof. It is produced by heating a mixture comprising an alkali water glass and a filler from the group of aluminum oxide, silicon dioxide, aluminous cement, crushed rocks, graphite with a blowing agent, and preferably azodicarbonamide, at temperatures of at least 180.degree. C., and preferably of from 200.degree. C. to 300.degree. C. The foam body has a bulk density within the range of from 50 to 500 kg/m.sup.3, and preferably of from 50 to 400 kg/m.sup.3.

Abstract: The invention relates to refractory materials which comprise:(A) grains of at least one refractory material whose melting point and thermal decomposition temperature are higher than 1700.degree. C.;(B) a binding matrix which binds these grains together and predominantly consists of aluminum nitride AlN of hexagonal structure and/or of at least one of the polytypes of AlN; and(C) hexagonal boron nitride particles and/or crystalline graphite flakes dispersed in the binding matrix.Applications in iron and steel metallurgy, in particular as plates in a slide closure device.

Abstract: A coated carbon body having improved resistance to high temperature oxidation and a method for producing the coated carbon body are described. The coated carbon body comprises a carbon body, an intermediate glass forming coating and an outer refractory coating on the intermediate coating. The body has a converted porous layer formed by etching and reacting the body with boron oxide and the resulting converted layer contains interconnecting interstices and boron carbide formed by the reaction of the boron oxide and the carbon body. The method comprises contacting a carbon body with boron oxide at an elevated temperature sufficient to cause the reaction between the carbon body and boron oxide to form a converted porous layer which contains interconnecting interstices in the body and boron carbide and then applying the glass forming coating over the converted layer. Preferably an outer refractory coating is applied over the glass forming coating.

Abstract: A carbon powder is disclosed with 40 to 75% by weight QI or more than 90% by weight TI, an optical anisotropy of less than 50% by volume, a start of softening between 200.degree. and 300.degree. C., and an oxygen content of more than 2% by weight, and which can be used for without binding agent the production of shaped carbon bodies. The carbon powder is produced by means of distillation from bituminous product at a maximum of 5 mbars and a final temperature of at least 400.degree. C., grinding of the distillation residue to a particle size of less than 30 .mu.m, and oxidation of the powder into the particle core.

Abstract: A carbon micro-sensor electrode is disclosed which is prepared by impregnating, adsorbing or chemically modifying a pure composite carbon wire having many micropores extending to its surface and interior with a reactant such as an enzyme, a metal complex compound, an organic compound or a metabolite; and a method for preparing this carbon micro-sensor electrode is also disclosed.The above-mentioned electrode can be used for a long period of time, since the reactant is received in the many micropores. Furthermore, after used, the electrode may be cut off to expose a new electrode surface, and this new electrode surface may be coated with a material which does not impede an electrode reaction, whereby the reactant can be prevented from flowing out. Thus, the carbon micro-sensor electrode of the present invention can be repeatedly utilized.

Abstract: Provided is a composite material for sliding members which comprises a titanium carbide matrix and graphite particles excellent in crystallinity which are uniformly dispersed in the titanium carbide matrix. This composite material has self-lubricity and high wear resistance together with the excellent properties of titanium carbide such as high strength, high hardness, high melting point, low specific gravity and high electrical conductivity.

Abstract: Provided is a carbonaceous binder composition which comprises a polymerized and dehydrated carbohydrate, a monomer or polymer of resorcinol, and water. It is important that the carbohydrate is a polymer when combined with the remaining components of the composition. Polymerization of the carbohydrate prior to being combined with the other components of the composition has been found to result in an increased carbon yield upon pyrolysis of the binder. The binder composition also has an effective shelf life of three months or longer and gives off no objectionable smell either before or after being pyrolyzed. More importantly, the binder is also free of any skin or respiratory irritants, and is in effect non-carcinogenic.

Abstract: Composites of flexible graphite particles and an amorphous carbon phase useful for applications such as valve packing end rings.

Abstract: A burned, high-purity refractory, specifically a chrome-alumina, alumina-chrome and picrochromite composition, which contains less than 5 ppm total soluble chromium. Such products are obtained by adding to the starting mix less than 5 wt. % (often less than 3 wt. %) zircon, titania, molybdic oxide, boric acid, carbon black, or silica.

Abstract: Diamond-containing ceramic composites useful as substrates and the like in the electronics industry as well as for abrasive and cutting applications and methods of making same are disclosed. More specifically, the sol-gel process is used to fabricate the composites by combining water, an organometallic precursor compound, alcohol or similar solvent between the water and the precursor compound, a catalyst, diamond powder and a thickening agent to form a moldable, wet, porous gel which can be dried at a temperature below the boiling point of any of the gel liquids to form a stabilized porous composite. The stabilized porous composite can be densified, by heat, in an essentially oxygen-free atmosphere to form a diamond-containing ceramic composite having low porosity.

Abstract: A carbon fiber reinforced carbon of the present invention is composed of a sintered body comprising precursor carbonaceous fiber and self-sintering carbonaceous powder with the precursor carbonaceous fiber buried therein. Since the precursor carbonaceous fiber working as a reinforcement and the self-sintering carbonaceous powder working as a binder come to have substantially the same physical properties (strength, shrinkage rate and the like), the boudary adhesion between them improves, thereby giving the sintered body high strength and excellent abrasion resistance. When the precursor carbonaceous fiber is subjected to a surface treatment using a viscous material, the wettability of the surface of the precursor carbonaceous fiber increases, thereby further improving the boundary adhesion between the precursor carbonaceous fiber and the self-sintering precursor carbonaceous powder.

Abstract: A refractory material possessing excellent erosion, thermal shock and oxidation resistance, as well as resistance to oxide build up useful in continuous casting of steel for use in such articles as tundish shrouds, particularly for slagline sleeves, bore liners and upper seating areas in such shrouds, as well as for stopper rod noses. The material consists of the following by weight: (a) carbon, from about 4% to about 50%; (b) one or more members selected from the group consisting of zirconium di-boride and titanium di-boride in an amount of from about 10% to about 90%; and (c) one or more members selected from the group consisting of zirconia, SiAlON, clay, alumina, magnesia, silica, silicon carbide, silicon nitride, boron nitride, mullite and chromia in an mount of from about 10% to about 80%.

Abstract: Disclosed is a sliding member having a predetermined shape and including: a sintered body obtained by sintering a composite body including: preliminary carbonized carbonaceous fiber; inorganic powder or inorganic fiber; and self-sintering carbonaceous powder with the preliminarily carbonized carbonaceous fiber and the inorganic powder or the inorganic fiber buried therein. The sliding member has a high and stable friction coefficient (.mu.), high strength, excellent abrasion resistance, and is manufacturable at a low cost. Further, the friction coefficient (.mu.) and the other properties of the sliding member can be controlled depending on an application of a sliding member by selecting an optimum inorganic powder or inorganic fiber. Particularly, when boron compound powder is selected as the inorganic powder, the friction coefficient (.mu.) of the sliding member can be suppressed to 0.15 or less, and the load at seizure thereof can be improved to 100 kgf/cm.sup.2 or more.

Abstract: An improved carbon/metal composite is disclosed which comprises a carbon matrix and metal fibers distributed in the carbon matrix. The improvement is that the metal fibers are selected from (A) metal fibers in which the surfaces of at least a portion of the fibers are coated or alloyed with another material which has a tendency to form carbides which is equal to or lower than that of the metal constituting the metal fibers, (B) metal fibers comprising at least two different types of metal fibers which differ with respect to their dimensions and/or material, and (C) metal fibers distributed in the carbon matrix in such a manner that their content varies along the thickness of the composite, thereby imparting to the composite improved properties with respect to at least one of mechanical strength, impact resistance, wear resistance, and electric conductivity.

Abstract: Ceramic matrix composite articles comprising a matrix phase composed of a silicate glass or glass-ceramic and a matrix reinforcement material disposed within the matrix comprising carbon (e.g., graphite) fibers are described, wherein the fibers are provided with a protective boron nitride surface coating. The mechanical properties of the composites at high temperatures are substantially improved.

Abstract: A dome forming sliding gate filling composition for teeming ladles comprises chrome ore sand, quartz sand, and fine grained carbon black as an additive which improves dome formation or increases pourability.

Abstract: Process for production of a ceramic material, e.g. a carbide, nitride, boride or silicide, by reacting at least one compound of a metallic or non-metallic element having two or more groups reactive with hydroxyl groups with at least one organic compound having two or more hydroxyl groups to form an oxygen-containing polymeric product, heating the polymeric product to produce a coked product containing carbon and an oxide of the metallic or non-metallic element, and heating the coked product to produce a ceramic material, in which the proportion by weight of carbon to the oxide of the metallic or non-metallic element in the coked product is in the range from 50% to 150% of the proportion which is theoretically required to produce the ceramic material.

Abstract: Boron nitride is coated on filaments of elemental carbon and/or silicon carbide, the coated filaments are contacted with an infiltration-promoting material containing elemental carbon to produce a preform wherein the filaments are substantially parallel and each filament is enveloped with infiltration-promoting material, and the preform is infiltrated with a molten solution of boron and silicon producing a composite containing boron nitride coated filaments.

Abstract: An organoaluminum polymer formed from R.sub.3 A1 and dialkylaluminum amide that is useful for forming shaped articles of inorganic aluminum nitride alone or with nitrides (other than AlN), oxides, borides, carbides or combinations thereof; R being selected from hydrogen; C.sub.1 to C.sub.10 alkyl; halogen; and substituted or unsubstituted phenyl, naphthyl and biphenyl; no more than two of the R groups being alkyl.

Abstract: A ceramic composite is produced wherein the matrix is comprised of silicon nitride and cordierite and the reinforcing phase is comprised of Si-C-containing fibers.

Abstract: A sintered article of diamond is obtained by coating the surface of diamond particles with 30 to 0.1% by volume, based on the total volume of the diamond particles and aids, of at least one member selected from the group consisting of the transition metals of Groups 4a, 5a, and 6a in the Periodic Table of Elements and boron and silicon, and sintering the coated diamond particles under conditions of high pressure and high temperature, which sintered article consists of 70 to 99.8% by volume of diamond and 30 to 0.2% by volume of the carbide of the coating substance. A method for the production of the sintered article of diamond is also disclosed.

Abstract: A siliconized graphite for use in mechanical seals is provided. This material is prepared by reacting graphite at an elevated temperature ranging from 1800.degree. to 2100.degree. C. with silicon monoxide. Silicon monoxide is generated in rate-controlled fashion by reacting either silicon carbide and silica or silicon nitride and silica at an elevated temperature ranging from 1500.degree. to 1800.degree. C.Although the optimum temperature range for the SiO generation and the siliconization of graphite is different by 300.degree. C., size-controlled raw materials (silicon carbide, silicon nitride, and silica) and a unique sample loading method make the whole process occurred in situ and make the production of mechanical seals efficient. Size-controlling of the raw materials is essential for a constant supply of silicon monoxide in controlled fashion, and a unique sample loading method is essential to put the SiO generation and the siliconization of graphite within their optimum temperature ranges.

Abstract: A resin bonded refractory composition of increased pressability and consequently increased density and strength is made by adding potassium borate to prior art refractory compositions.

Abstract: A carbonized composite foam having a density less than about 50 mg/cm.sup.3 and individual cell sizes no greater than about 1 .mu.m in diameter is described, and the process of making it.

Abstract: A process of forming a coherent refractory mass on a surface comprises projecting against that surface, together with oxygen, a mixture of refractory particles and fuel which reacts in an exothermic manner with the projected oxygen to release sufficient heat to melt at least the surfaces of the refractory particles and thus form the refractory mass. The projected mixture contains, as fuel, finely divided particles of at least one element which is oxidizable to form a refractory oxide and it also contains carbonaceous particles which are of such a size or composition that carbon particles become occluded in the formed refractory mass. The mixture may contain, as said fuel, finely divided particles having a mean grain size of less than 50 .mu.m of silicon, aluminum and/or magnesium. The carbonaceous particles may comprise a carbonaceous core which is covered by a mantle inhibiting oxidation of the core.

Abstract: A superior release coating for glass-encapsulated ceramic or ceramic composite bodies in hot isostatic pressing processes is obtained by mixing boron nitride with up to about 30% by weight of carbon.

Abstract: A method for manufacturing silicon carbide whisker which has a cross-sectional diameter of greater than about 1 .mu.m by mixing a source of silicon atom in the form of grains having a mean grain diameter of at least 50 .mu.m with a carbon atom source in the presence of an element or compound of the element, the element being yttrium, calcium, manganese, aluminum, indium, or rare earth elements in an amount from about 100 to 2,000 ppm and growing the silicon carbide whisker therefrom.

Abstract: A novel isotropically reinforced microcomposite is described. An entirely fluid-phase method has been devised for producing the net-shape filamentary structures. The process depends for its success on the ability to generate in situ, within a shaped mold, a three-dimensional random weave of carbon filaments by catalytic decomposition of a hydrocarbon feed. Almost any desired filament filler matrix combination can be produced by utilizing chemical vapor deposition to modify the surface and bulk properties of the filamentary structure. Infiltration of filler matrix materials can be achieved by adaptation of existing materials technologies.

Abstract: High pressure sintered bodies of polycrystalline diamond or carbide ceramics are rendered more resistant to cracking by establishing dispersed, localized "stress centers" of submicron size particles of lonsdaleite, diamond, or other form of metastable, high density carbon which has the capability of transforming crystallographically to graphite in situ in the body. When an incipient crack in the body approaches entrapped metastable particles along its path, the crack promotes or permits transformation of the metastable particles to graphite particles, with concomitant increase in their size, thereby resisting further propagation of the crack.

Abstract: Self-supporting bodies are produced by reactive infiltration of a parent metal into boron carbide typically resulting in a composite comprising a boron-containing compound and metal. The mass to be infiltrated may contain one or more inert fillers admixed with the boron carbide, or at least one carbon donor material, to produce a composite by reactive infiltration, which composite comprises a matrix of metal and boron-containing compound embedding the filler. In one embodiment of the invention, a parent metal is reactively infiltrated into a mass comprising a boron carbide material mixed with a carbon-containing compound. In this embodiment, a self-supporting composite is formed typically comprising a boron-containing compound, a carbon-containing compound, and metal. The relative amounts of reactants and process conditions may be altered or controlled to yield a body containing varying volume percents of ceramic, metal and/or porosity.

Abstract: There is disclosed a raw composition, as well as a fired shape, known in the art as a clay-bonded graphite crucible for melting metals, which contains a quantity of fused silica and is particularly adaptable to melting metals in high-energy, induction furnaces.

Abstract: A high-toughness silicon carbide composite ceramic comprising silicon carbide, 5 to 50 vol % of graphite whiskers, and sintering aid, and a method for producing the composite ceramic. The composite ceramic has high-temperature strength and fracture toughness value, and also has electrical conductivity.

Abstract: In processes of forming a refractory mass on a surface, a mixture of refractory particles and oxidizable particles which react exothermically with oxygen to generate sufficient heat to soften or melt at least the surfaces of the refractory particles are sprayed against that surface to bring about formation of said refractory mass. To promote the reliable and consistent formation of a durable refractory mass, the granulometry of the particles which are sprayed in the mixture is such that the 80% and 20% grain sizes of the refractory particles (that is, the screen mesh sizes G.sub.80 and G.sub.20 through which respectively 80% and 20% by weight of the particles will pass) have a mean greater than the mean of the 80% and 20% grain sizes of the oxidizable particles and the size range spread factor f(G) of the refractory particles is at least 1.

Abstract: A refractory liner composition which consists essentially of carbon and a composite selected from the group consisting of zirconia and O'-sialon and zirconia and silicon oxynitride.

Abstract: A furnace for sintering non-oxide ceramics, particularly Si.sub.3 N.sub.4, which includes a space for accommodating a ceramic shaped body, carbon heaters arranged around the ceramic shaped body in said space and heat insulating layers of carbon fiber mat that cover the inner walls of the furnace. The furnace also includes sheets composed of laminated graphite leaves having an ash content of not more than 0.3% by weight extendedly provided between the heat insulating layers and the ceramic shaped body. As the carbon heaters, those composed of a high purity graphite having a carbon content of at least 99.9980%, a silicon content of not more than 5 ppm and an iron content of not more than 9 ppm, by weight, are preferably used. A process is also disclosed which utilizes the above apparatuses to protect the shaped body from an influence of carbon fiber dusts liberating from the insulating layers during sintering.

Abstract: A sintered article of diamond is obtained by coating the surface of diamond particles with 30 to 0.1% by volume, based on the total volume of the diamond particles and aids, of at least one member selected from the group consisting of the transition metals of Groups 4a, 5a, and 6a in the Periodic Table of Elements and boron and silicon, and sintering the coated diamond particles under conditions of high pressure and high temperature, which sintered article consists of 70 to 99.8% by volume of diamond and 30 to 0.2% by volume of the carbide of the coating substance. A method for the production of the sintered article of diamond is also disclosed.

Abstract: The preparation of highly densified ceramic bodies by sintering certain curable organopolysiloxanes filled with silicon carbide powders, metal-containing sintering aids, and organopolysiloxane curing agents described. Such highly densified ceramic bodies can be prepared by either a pressure-less or a hot press sintering process. The compositions of this invention can be formed into desired shapes and then sintered to form ceramic, shaped bodies with high densities. One advantage of the present invention is that the green bodies have relative high strengths and thus can be easily handled and, if desired, machined before sintering. The curable organopolysiloxanes useful in this invention must yield a ceramic char which contains free or excess carbon in addition to carbon in the form of silicon carbide upon pyrolysis to elevated temperatures.

Abstract: The invention relates to glass fiber compositions and fibers having use as a reinforcement element of cement-base products. As such, the composition is able to resist attack of strongly basic media.The fibers of the invention comprise the following constituents, in proportions by weight:SiO.sub.2 --56 to 68%,ZrO.sub.2 --14 to 17%,Na.sub.2 O--12 to 20%,K.sub.2 O--0 to 8%,Al.sub.2 O.sub.3 --1 to 9%,and wherein the sum of Na.sub.2 O and K.sub.2 O is between 14 and 22%, and wherein the sum of SiO.sub.2 and Al.sub.2 O.sub.3 is less than 70%.

Abstract: An electric motor brush or other electrical contact fabricated with intercalated graphite exhibits improved electrical conductivity, strength and performance when compared with electrical brushes made with non-intercalated graphite or with carbon. Such contacts may be formed by filling a mold of the appropriate shape with intercalated graphite powder and applying sufficient pressure and heat to produce a coherent mass. The ability of intercalated graphite powder to be compacted in such a fashion leads to economic methods of manufacturing electrical contacts. The properties of these contacts may be further improved by the incorporation of metal powder, organic polymers or ceramic powders into the intercalated graphite prior to pressing.

Abstract: Described herein is a method for producing a carbon-ceramic composite material, which is characterized by firing a ground powder mixture of low temperature coke and a ceramic material in a non-oxidizing atmosphere at a temperature higher than 800.degree. C., inclusive, and lower than an inceptive sintering temperature of the ceramic material, prior to shaping and sintering stages.

Abstract: A reinforcing inorganic fiber composed of an internal layer and a surface layer, whereinsaid internal layer is composed of an inorganic material containing silicon, either titanium or zirconium, carbon and oxygen which is(i) an amorphous material consisting substantially of Si, M, C and O, or(ii) an aggregate consisting substantially of ultrafine crystalline particles with a particle diameter of not more than 500 .ANG. of .beta.-SiC, MC, a solid solution of .beta.-SiC and MC and MC.sub.1-x, wherein M represents titanium or zirconium, and x is a number represented by 0<x<1, or(iii) a mixture of the amorphous material (i) and the aggregate (ii), andsaid surface layer is composed of an inorganic material consisting of silicon, either titanium or zirconium, and oxygen and optionally not more than 5% by weight of carbon which is(iv) an amorphous material consisting substantially of Si, M and O,(v) an aggregate composed of crystalline SiO.sub.2 and MO.sub.

Abstract: A process for fabrication of refractory insulating materials wherein essentially pure silica shells are mixed with a polymeric graphite precursor dissolved in a solvent. The resulting slurry is placed in a forming mold, and the solvent is evaporated to form a polymeric matrix containing the shells as a dispersion. This matrix is pyrolized under an inert or reducing atmosphere to decompose the polymer and form a first product consisting essentially of a carbon matrix containing a dispersion of silica shells. To enhance refractory characteristics, such first product is fired at high temperature in an inert or reducing atmosphere to form a second product consisting of a carbon matrix containing a dispersion of SiC-lined voids, or in a nitrogen atmosphere to form a third product consisting of the carbon matrix containing a dispersion of Si.sub.3 N.sub.4 -lined voids.

Abstract: The invention is concerned with the production of pencil leads and also pencil leads as produced by the proposed method. In accordance with the invention, graphite, enamel frit and quartz flour, preferably at least approximately in a ratio of one part of graphite, two to four parts of enamel frit and one part of quartz flour, are processed to form a starting mixture which is then pressed into the form of a lead, is dried and is fired. The invention renders it possible to perform sintering below a temperature of 550.degree. C. and, accordingly, to perform the sintering firing operation in a normal oxidizing atmosphere.

Abstract: Aluminum nitride structures are made by pyrolyzing the condensation products of certain organo-aluminum compounds with certain aromatic diamines, triamines or tetraamines.

Abstract: Disclosed herein is a high temperature-resistant and abrasion-resistant sliding member of graphite-metal borides showing a friction coefficient of 0.01 to 0.09 and a specific amount of abrasion of 1.0 to 4.0.times.10.sup.-8 mm.sup.2 /kg under the measuring conditions of a load of 20 kg/cm.sup.2 and a sliding velocity of 5 m/min at an atmosphere temperature of 300.degree. C., a bending strength of 230 to 900 kg.f/cm.sup.2 and a Shore hardness of 28 to 45, produced by sintering (a) 70 to 93% by weight of amorphous carbon powder, (b) 5 to 20% by weight of at least one boride of a metal of IVa group, Va group of VIa group of the periodic table and (c) 2 to 10% by weight of powdery natural graphite, powdery Kish graphite or a mixture thereof.

Abstract: This invention relates to high-hardness, high-toughness, high-density composite materials containing diamond, and a process for making such materials comprising applying shock compression to the composite powders and inducing an exothermic chemical reaction. The process is useful in making metal, ceramic and cermet diamond composite materials.

Abstract: A polycrystalline diamond (PCD) body with improved thermal stability is disclosed which comprises a PCD body which has had at least one of its previously empty pores infiltrated by a silicon containing alloy. According to the process of the invention, a porous PCD body is obtained, preferably by acid leaching a PCD body which was formed in the presence of a metal catalyst such as cobalt. The porous PCD body is then surrounded by either the desired silicon containing alloy, or by the constituents of that alloy, each preferably in powdered form. The PCD body with its surrounding material is then heated and pressed to temperatures sufficient to melt the surrounding material (thereby forming the silicon alloy if not already formed) and to cause it to infiltrate into the pores. After the infiltration, it is preferred to remove the excess silicon containing alloy from the external surfaces of the PCD body, such as by an acid bath. It is also preferred to include several porous PCD bodies per process cycle.

Abstract: Disclosed herein is a method and composition of matter for constructing temperature resistant parts for the metal making industry from a mix of refractory fibers and Silca-carbon in the form of burned rice hull ash.