And Carbonaceous Material Patents (Class 501/90)
-
Patent number: 6774073Abstract: The invention provides exemplary silicon carbide ceramic bodies and processes for making such ceramic bodies. In one embodiment, a raw batch for producing a ceramic body includes a silicon carbide slurry and agglomerates of particles defining a dry lubricant mixture. The mixture includes a binder and a dry lubricant such as graphite, with a majority of the agglomerates having a shape that is generally spherical.Type: GrantFiled: July 29, 2002Date of Patent: August 10, 2004Assignee: CoorsTek, Inc.Inventor: Eric G. Wilkins
-
Patent number: 6762140Abstract: The present application is directed to ceramic compositions and, more specifically, to a silicon carbide composition and method of making it through liquid phase sintering. In one embodiment, the present invention is directed to an unsintered ceramic body including at least one liquid phase sintering aid. The unsintered ceramic body further includes a boron containing compound, a free carbon containing compound, and silicon carbide. In another embodiment, the present invention is directed to a method of making a sintered ceramic body. The method includes combining at least one liquid phase sintering aid, a boron containing compound, a free carbon containing compound, and silicon carbide to form a green ceramic, shaping the green ceramic into a ceramic body, and sintering the ceramic body.Type: GrantFiled: April 29, 2002Date of Patent: July 13, 2004Assignee: Saint-Gobain Ceramics & Plastics, Inc.Inventors: Vimal K. Pujari, William T. Collins, Matteo Scalabrino
-
Patent number: 6716800Abstract: A composite body of silicon carbide having binderless, allotropic carbon granules distributed throughout is produced. The nominal size of the binderless allotropic carbon granules can range from 5 to 500 micrometers. The concentration of the binderless allotropic carbon particles can vary from 1.0 to 35.0 weight percent. The process to produce such a composite body is to sinter silicon carbide with binderless, carbon-yielding precursor granules. The composite body is utilized in tribological applications. The dense, impervious silicon carbide-binderless carbon composite exhibits excellent physical and tribological characteristics when used as a mechanical face seal, a sliding bearing arrangement, or some other rubbing component.Type: GrantFiled: April 12, 2002Date of Patent: April 6, 2004Assignee: John Crane Inc.Inventors: Joseph F. Demendi, Xin Chen, William R. Clemens
-
Publication number: 20040018935Abstract: The invention provides exemplary silicon carbide ceramic bodies and processes for making such ceramic bodies. In one embodiment, a raw batch for producing a ceramic body includes a silicon carbide slurry and agglomerates of particles defining a dry lubricant mixture. The mixture includes a binder and a dry lubricant such as graphite, with a majority of the agglomerates having a shape that is generally spherical.Type: ApplicationFiled: July 29, 2002Publication date: January 29, 2004Applicant: CoorsTek, Inc.Inventor: Eric G. Wilkins
-
Patent number: 6680267Abstract: The present application is directed to ceramic compositions and, more specifically, to a silicon carbide composition and method of making it through liquid phase sintering. In one embodiment, the present invention is directed to an unsintered ceramic body including a rare earth metal oxide, one of a glass phase metal oxide and a glass phase metal nitride, a boron containing compound, a free carbon containing compound and silicon carbide. In another embodiment, the present invention is directed to a method of making a sintered ceramic body. The method includes combining a rare earth metal oxide, one of a glass phase metal oxide and a glass phase metal nitride, a boron containing compound, a free carbon containing compound, and silicon carbide to form a green ceramic. The method further includes shaping the green ceramic into a ceramic body and sintering the ceramic body.Type: GrantFiled: August 20, 2001Date of Patent: January 20, 2004Assignee: Saint-Gobain Ceramics & Plastics, Inc.Inventors: Vimal K. Pujari, William T. Collins
-
Patent number: 6670294Abstract: Corrosion-resistive ceramic materials include a silicon based ceramic, wherein a percentage of respective metal elements other than metal elements constituting sintering agents and silicon is not more than 10 weight ppm. The corrosion-resistive ceramic materials show a high corrosion resistance with respect to corrosive substances and suppress particle generation due to an exposure to corrosive substances. Therefore, chippings and cracks do not occur easily during machining work.Type: GrantFiled: January 23, 2002Date of Patent: December 30, 2003Assignee: NGK Insulators, Ltd.Inventor: Hiromichi Kobayashi
-
Publication number: 20030195122Abstract: A composite body of silicon carbide having binderless, allotropic carbon granules distributed throughout is produced. The nominal size of the binderless allotropic carbon granules can range from 5 to 500 micrometers. The concentration of the binderless allotropic carbon particles can vary from 1.0 to 35.0 weight percent. The process to produce such a composite body is to sinter silicon carbide with binderless, carbon-yielding precursor granules. The composite body is utilized in tribological applications. The dense, impervious silicon carbide-binderless carbon composite exhibits excellent physical and tribological characteristics when used as a mechanical face seal, a sliding bearing arrangement, or some other rubbing component.Type: ApplicationFiled: April 12, 2002Publication date: October 16, 2003Applicant: John Crane Inc.Inventors: Joseph F. Demendi, Xin Chen, William R. Clemens
-
Patent number: 6632761Abstract: A silicon carbide powder which can increase the densities of a green body and a sintered silicon carbide, a method of producing a green body having a high density and excellent handling properties, and a method of producing a sintered silicon carbide having a high density, in which methods the silicon carbide powder is used. The silicon carbide powder includes at a particulate volume ratio of 20% to 80% a silicon carbide powder whose model ratio is 1.7 &mgr;m to 2.7 &mgr;m and a silicon carbide powder whose model ratio is 10.5 &mgr;m to 21.5 &mgr;m. The silicon carbide powder is used in the method of producing a green body and in the method of producing a sintered silicon carbide powder.Type: GrantFiled: August 15, 2000Date of Patent: October 14, 2003Assignee: Bridgestone CorporationInventors: Kazuhiro Ushita, Fumio Odaka, Yoshitomo Takahashi
-
Publication number: 20030109371Abstract: The present application is directed to ceramic compositions and, more specifically, to a silicon carbide composition and method of making it through liquid phase sintering. In one embodiment, the present invention is directed to an unsintered ceramic body including at least one liquid phase sintering aid. The unsintered ceramic body further includes a boron containing compound, a free carbon containing compound, and silicon carbide. In another embodiment, the present invention is directed to a method of making a sintered ceramic body. The method includes combining at least one liquid phase sintering aid, a boron containing compound, a free carbon containing compound, and silicon carbide to form a green ceramic, shaping the green ceramic into a ceramic body, and sintering the ceramic body.Type: ApplicationFiled: April 29, 2002Publication date: June 12, 2003Inventors: Vimal K. Pujari, William T. Collins, Matteo Scalabrino
-
Publication number: 20030054939Abstract: The present application is directed to ceramic compositions and, more specifically, to a silicon carbide composition and method of making it through liquid phase sintering. In one embodiment, the present invention is directed to an unsintered ceramic body including a rare earth metal oxide, one of a glass phase metal oxide and a glass phase metal nitride, a boron containing compound, a free carbon containing compound and silicon carbide. In another embodiment, the present invention is directed to a method of making a sintered ceramic body. The method includes combining a rare earth metal oxide, one of a glass phase metal oxide and a glass phase metal nitride, a boron containing compound, a free carbon containing compound, and silicon carbide to form a green ceramic. The method further includes shaping the green ceramic into a ceramic body and sintering the ceramic body.Type: ApplicationFiled: August 20, 2001Publication date: March 20, 2003Inventors: Vimal K. Pujari, William T. Collins
-
Patent number: 6531423Abstract: The invention relates to a polycrystalline SiC shaped body, which consists of 96% by weight to 99.5% by weight of hard-material grains having a core/shell structure, 0 to 0.1% by weight free carbon, remainder a partially crystalline binder phase; having the following properties: density at least 99.5% of the theoretical density, dark green coloring of ground sections or polished surfaces through characteristic light absorption in the orange spectral region at 1.8 to 2.2 eV, resistivity of at least 107 ohm·cm, and fracture toughness of at least 4.0 MPa.m½, measured using the bridge method.Type: GrantFiled: July 8, 2000Date of Patent: March 11, 2003Assignee: Wacker-Chemie GmbHInventors: Karl-Alexander Schwetz, Lorenz Sigl, Thomas Kempf, Georg Victor
-
Publication number: 20020160902Abstract: A ceramic composite material with a density of >90% of the theoretical density based on SiC and carbon, with a silicon carbide content of between 99.9% by weight and 70% by weight and a carbon content of between 0.Type: ApplicationFiled: March 7, 2002Publication date: October 31, 2002Inventors: Christoph Lesniak, Lorenz Sigl, Armin Kayser
-
Patent number: 6398991Abstract: Exemplary silicon carbide ceramic bodies having inclusions therein are produced according to the invention. An exemplary ceramic body includes silicon carbide in major amounts and unreacted particles of an additive in minor amounts which are bonded to the matrix. The particles are dispersed throughout the silicon carbide, and are preferably selected from one or more of the group consisting of boron nitride, aluminum nitride and titanium diboride.Type: GrantFiled: June 23, 2000Date of Patent: June 4, 2002Assignee: CoorsTek, Inc.Inventors: Steven M. Brazil, Eric G. Wilkins
-
Patent number: 6387834Abstract: A method for producing a sintered silicon carbide body which has excellent strength and the like and in which cracking and breaking are prevented is provided. In the method for producing a sintered silicon carbide body, metallic silicon is, in a vacuum atmosphere or in a non-oxidizing atmosphere, impregnated into a molded body containing silicon carbide and carbon so as to form an impregnated body, and the impregnated body is cooled in a state of being provided with a temperature distribution of 0.1-1.5° C./cm.Type: GrantFiled: May 26, 2000Date of Patent: May 14, 2002Assignee: Bridgestone CorporationInventors: Fumio Odaka, Kazuhiro Ushita, Yoshitomo Takahashi
-
Publication number: 20020005213Abstract: A sintered silicon carbide has a high density and only small amounts of organic and inorganic impurities on the surface and in the vicinity of the surface, i.e., a density of 2.9 g/cm2 or more and an amount of each impurity smaller than 1.0×1011 atoms/cm2 on the surface and in the vicinity of the surface. A method for cleaning sintered silicon carbide in a wet condition comprises treating sintered silicon carbide in a step of dipping into a quasi-aqueous organic solvent, a step of dipping into an aqueous solution of an ammonium compound, a step of dipping into an aqueous solution of an inorganic acid and a step of dipping into pure water. Organic and inorganic impurities present on the surface and in the vicinity of the surface of the sintered silicon carbide are removed easily in accordance with the method.Type: ApplicationFiled: November 26, 1999Publication date: January 17, 2002Inventors: MASASHI OTSUKI, HIROAKI WADA
-
Publication number: 20010021686Abstract: The invention relates to a carbon-graphite material with an embedded additive. So that the carbon-graphite material is distinguished by a low coefficient of friction and low wear, it is proposed that the additive is one or several synthetic mechanically resistant materials of a mean grain size between 0.1 to 10 &mgr;m.Type: ApplicationFiled: June 19, 1997Publication date: September 13, 2001Inventors: GUNTER RINN, HANS LIPPER, RAINER SPERLING, KARL-HEINZ SAUER
-
Patent number: 6288001Abstract: A graphite-containing monolithic refractory material comprises at least one component selected from alumina and alumina-magnesia spinel, which are divided into selected particle size regions, artificial graphite having a selected average particle size, and pitch powder. The refractory material may optionally comprise a selected amount of silicon carbide having a selected average particle size. The graphite-containing monolithic refractory material exhibits excellent casting workability at a low moisture content, and both excellent corrosion resistance and spalling resistance. The refractory material is suitable as a casting monolithic refractory material for lining a topedo ladle car.Type: GrantFiled: December 22, 1998Date of Patent: September 11, 2001Assignee: Kawasaki Steel CorporationInventors: Yoshisato Kiyota, Masato Kumagai, Masao Nanbu, Shigenobu Takata, Masakazu Iida, Noboru Komatsubara, Toyohide Yamaguchi
-
Patent number: 6264045Abstract: 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.Type: GrantFiled: May 29, 1998Date of Patent: July 24, 2001Assignee: Hitco Carbon Composites, Inc.Inventors: Doug Wilson, Raj Mathur
-
Patent number: 6261981Abstract: The invention provides a fiber-reinforced composite ceramic containing high-temperature-resistant fibers, in particular fibres based on Si/C/B/N, which are reaction-bonded to a matrix based on Si, which is produced by impregnating fiber bundles of Si/C/B/N fibers with a binder suitable for pyrolysis and solidifying the binder, if desired subsequently conditioning the fiber bundles with an antisilicization layer suitable for pyrolysis, for example phenolic resin or polycarbosilane, subsequently preparing a mixture of fiber bundles, fillers such as SiC and carbon in the form of graphite or carbon black and binders, pressing the mixture to produce a green body and subsequently pyrolysing the latter under reduced pressure or protective gas to produce a porous shaped body which is then infiltrated, preferably under reduced pressure, with a silicon melt.Type: GrantFiled: March 28, 2000Date of Patent: July 17, 2001Assignee: DaimlerChrysler AGInventors: Gerd Dietrich, Tilmann Haug, Andreas Kienzle, Christian Schwarz, Heike Stöver, Karl Weisskopf, Rainer Gadow
-
Patent number: 6217969Abstract: A sputtering target disk is provided which is comprised of a sintered silicon carbide having a density of 2.9 g/cm3 or more and obtained by sintering a uniform mixture of a powder of silicon carbide and a nonmetallic auxiliary sintering agent. The sputtering target disk is advantageously used in a sputtering treatment to form thin films with high purity which are suitable for use in various parts of electronic devices. The sputtering target disk exhibits excellent mechanical properties, electric properties, and durability against uneven wear.Type: GrantFiled: August 21, 1998Date of Patent: April 17, 2001Assignee: Bridgestone CorporationInventors: Yoshitomo Takahashi, Hiroaki Wada, Akira Satou
-
Patent number: 6214755Abstract: A sintered silicon carbide containing nitrogen is obtained by sintering a mixture of a powder of silicon carbide and a nonmetallic auxiliary sintering agent. The sintered silicon carbide has a density of 2.9 g/cm3 or more and contains 150 ppm or more of nitrogen. The sintered silicon carbide preferably has a volume resistivity of 1 &OHgr;·cm or less and contains &bgr;-silicon carbide in an amount of 70% or more of total silicon carbide components. Nitrogen can be introduced into the sintered silicon carbide by adding a nitrogen source, for example, an amine such as hexamethylenetetramine, ammonia, and triethylamine in the production of the powder of silicon carbide which is used as the material powder for producing the sintered silicon carbide or by adding the nitrogen source in combination with the nonmetallic auxiliary sintering agent in the production of the sintered silicon carbide.Type: GrantFiled: April 7, 2000Date of Patent: April 10, 2001Assignee: Bridgestone CorporationInventors: Masashi Otsuki, Hiroaki Wada, Yoshitomo Takahashi, Tasuku Saito
-
Patent number: 6187704Abstract: 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.Type: GrantFiled: August 24, 1998Date of Patent: February 13, 2001Assignee: Bridgestone CorporationInventors: Yoshitomo Takahashi, Hiroaki Wada, Akira Satou
-
Patent number: 6187256Abstract: A process is described for producing a conductive sintered body based on silicon carbide, in which a) silicon carbide particles, optionally pretreated with a surface modifier, are dispersed in an aqueous and/or organic medium and positive or negative surface charges are generated on the silicon carbide particles by adjustment of the pH of the dispersion obtained; b) carbon black and boron carbide are mixed in as sintering aids, where at least the carbon black particles have a surface charge opposite to the surface charge of the silicon carbide particles and the boron carbide can also be added, completely or in part, at a later point in time (stage c′)); c) the slip thus obtained is shaped directly to form a green body or c′) a sinterable powder is isolated from the slip obtained and is shaped to form a green body, where the above boron carbide can also be added to this sinterable powder; and d) the green body obtained is subjected to pressureless sintering to form a sintered body in essentialType: GrantFiled: April 8, 1998Date of Patent: February 13, 2001Assignee: Institut für Neue Materialen gemeinnützige GmbHInventors: Mesut Aslan, Rüdiger Nass, Helmut Schmidt
-
Patent number: 6132856Abstract: 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.Type: GrantFiled: July 17, 1998Date of Patent: October 17, 2000Assignee: Ube Industries, Ltd.Inventors: Toshihiro Ishikawa, Shinji Kajii, Kenji Matsunaga, Toshihiko Hogami
-
Patent number: 6127510Abstract: Novel C/N-- and B/C/N polymers which can be obtained by reaction of (a) a carbodiimide having the formula R.sub.3 E--NCN--ER.sub.3, in which R includes a group selected from the group consisting of alkyl groups and aryl groups, and E comprises a component selected from the group consisting of Si, Ge, and Sn, and (b) a halogenotriazine. Methods for making and using said polymers.Type: GrantFiled: August 10, 1999Date of Patent: October 3, 2000Assignee: Bayer AktiengesellschaftInventors: Ralf Riedel, Edwin Kroke, Axel Greiner
-
Patent number: 6121176Abstract: The invention concerns glasses that have a refractive index of more than 1.880, an Abbe number of more than or equal to 30.4, and a density of more than 4.1, and having the following chemical composition, expressed in wt. %, based on the oxides: SiO.sub.2 : 6-9, B.sub.2 O.sub.3 : 15-19, with SiO.sub.2 +B.sub.2 O.sub.3 <26, Nb.sub.2 O.sub.5 : 12 to <20.5, ZrO.sub.2 : 8-10, TiO.sub.2 : 7-11, La.sub.2 O.sub.3 : 23-32, with ZrO.sub.2 +TiO.sub.2 +La.sub.2 O.sub.3 : .gtoreq.44, CaO: 8 to <13, SrO: 0-2, BaO: 0-2, MgO: 0-2, ZnO: 0-5, with CaO+SrO+BaO+MgO+ZnO: .gtoreq.9, Y.sub.2 O.sub.3 : 0-5, WO.sub.3 : 0-5, Li.sub.2 O+Na.sub.2 O+K.sub.2 O: 0-2, others 0-1.Type: GrantFiled: July 9, 1999Date of Patent: September 19, 2000Assignee: Corning S.A.Inventor: Marie Jacqueline Monique Comte
-
Patent number: 6090733Abstract: A sintered silicon carbide containing nitrogen is obtained by sintering a mixture of a powder of silicon carbide and a nonmetallic auxiliary sintering agent. The sintered silicon carbide has a density of 2.9 g/cm.sup.3 or more and contains 150 ppm or more of nitrogen. The sintered silicon carbide preferably has a volume resistivity of 1 .OMEGA..multidot.cm or less and contains .beta.-silicon carbide in an amount of 70% or more of total silicon carbide components. Nitrogen can be introduced into the sintered silicon carbide by adding a nitrogen source, for example, an amine such as hexamethylenetetramine, ammonia, and triethylamine in the production of the powder of silicon carbide which is used as the material powder for producing the sintered silicon carbide or by adding the nitrogen source in combination with the nonmetallic auxiliary sintering agent in the production of the sintered silicon carbide.Type: GrantFiled: August 21, 1998Date of Patent: July 18, 2000Assignee: Bridgestone CorporationInventors: Masashi Otsuki, Hiroaki Wada, Yoshitomo Takahashi, Tasuku Saito
-
Patent number: 6030913Abstract: A composite material article reinforced with high strength short graphite fibers and having a matrix substantially consisting of silicon carbide is prepared which has an elongation at break of 0.25 to 0.5% and thus exhibits quasi-ductile failure behavior. The short reinforcing graphite fibers are enclosed by at least two shells of graphitized carbon which have been obtained by impregnation with carbonizable impregnating agents and subsequent carbonization. The shell closest to the graphite fibers contains no cracks. The outermost shell is partially converted into silicon carbide. The starting material used comprises long or short fiber prepregs, which are first carbonized, then subjected at least once to an operation consisting of impregnation with a carbonizable impregnating agent and recarbonization, then graphitized at a temperature of up to maximum of 2400.degree. C. and then comminuted to yield a dry material for the production of a precursor article.Type: GrantFiled: February 19, 1998Date of Patent: February 29, 2000Assignee: SGL Technik GmbHInventors: Michael Heine, Udo Gruber
-
Patent number: 6001756Abstract: A silicon carbide sintered body according to the present invention is a silicon carbide sintered body having a density of 2.9 g/cm.sup.3 or higher, obtained by means of hot pressing a mixture of silicon carbide powder and a non-metal-based sintering additive such as an organic compound which produces carbon upon heating at a temperature of 2,000.degree. C. to 2,400.degree. C. and under a pressure of 300 to 700 kgf/cm.sup.2 in a non-oxidizing atmosphere. It is preferable that the silicon carbide powder have an average particle diameter of from 0.01 to 10 .mu.m and that the non-metal sintering additive be a resol type phenol resin. The present invention is to provide a silicon carbide sintered body of high quality which has a high density, a high purity, and a high electrical conductivity and which is useful for semiconductor manufacturing industry.Type: GrantFiled: May 9, 1997Date of Patent: December 14, 1999Assignee: Bridgestone CorporationInventors: Yoshitomo Takahashi, Hiroaki Wada, Taro Miyamoto
-
Patent number: 5998318Abstract: There is provided a sintered silicon carbide with graphite added thereto having excellent lubrication characteristics. The sintered silicon carbide with graphite added thereto contains 10-30 wt. % of natural graphite flakes having an average grain size of 8-100 .mu.m and the remainder silicon carbide and a sintering aid, and having a relative density of 80-92%.Type: GrantFiled: March 10, 1998Date of Patent: December 7, 1999Assignees: Tanken Seal Seiko Co., Ltd., Syowa Denko K.K.Inventors: Hiroshi Takanami, Yukio Ishii, Mamoru Asuwa
-
Patent number: 5989467Abstract: The present invention is embodied in a ceramic foam made by mixing a liquid pre-ceramic resin and a liquid phenolic resin, allowing the resultant mixture to chemically foam, curing the mixture for a time and at a temperature sufficiently to convert the mixture to a polymeric foam, and then heating the resultant polymeric foam for a time and at a temperature sufficient to break-down polymers of the polymeric foam and convert the polymeric foam to a ceramic foam. The ceramic foam of the present invention contains residual decomposed components of the liquid phenolic resin and/or liquid pre-ceramic resin.Type: GrantFiled: March 4, 1997Date of Patent: November 23, 1999Assignee: Northrop Grumman CorporationInventors: David Eric Daws, Nicholas T. Castellucci, Harry Wellington Carpenter, Mary Wagner Colby
-
Patent number: 5972818Abstract: A raw batch for producing a crack-free recrystallized silicon carbide body, the raw batch comprising:i) at least 40 w/o fine grain fraction having a particle size of less than 10 microns, the fine grain fraction comprising silicon carbide and fine free carbon, wherein the fine free carbon is present in an amount of at least 0.10 w/o of the raw batch, the fine free carbon having a surface area of at least 10 m.sup.2 /g,ii) at least 40 w/o coarse grain fraction having a particle size of at least 30 microns, the coarse grain fraction comprising silicon carbide and coarse free carbon, wherein the coarse free carbon is present in an amount of at least 0.10 w/o of the coarse grain fraction,the raw batch having a total silica content of at least 0.5 w/o,the raw batch having a total silicon carbide content of at least 96 w/o.Type: GrantFiled: March 26, 1999Date of Patent: October 26, 1999Assignee: Saint-Gobain/Norton Industrial Ceramics CorporationInventors: Stephen Dynan, Jack Shindle, John Vayda
-
Patent number: 5968653Abstract: A carbon-graphite/silicon carbide composite article is provided. The composite article includes a carbon-graphite body intimately bonded to a dense silicon carbide body by a transition/bonding region which links the two bodies. The transition/bonding region between the carbon-graphite body and the silicon carbide body typically includes a layer rich in silicon metal and a small silicon carbide/silicon metal/carbon graphite area where some of the carbon-graphite from the carbon-graphite body has been converted to silicon carbide. The carbon-graphite body may also include a variety of impregnants.Type: GrantFiled: January 11, 1996Date of Patent: October 19, 1999Assignee: The Morgan Crucible Company, plcInventors: Steven J. Coppella, Laurence J. Thorwart, Mark E. Pfaff, David A. Erich
-
Patent number: 5962357Abstract: The object of the present invention is to provide a taphole mix for use in a molten metal taphole which has improved resistance to both wear and corrosion and enables prolonged tapping of iron and reduces difficult drilling. The taphole mix of the present invention is characterized in that it comprises a refractory base material in an amount of 65 to 92 wt % and a binder in an amount of 8 to 35 wt %, the binder consisting of an anhydrous coal tar having a fixed carbon content of 32.5 wt % or above.Type: GrantFiled: May 26, 1998Date of Patent: October 5, 1999Assignee: Shinagawa Refractories Co., Ltd.Inventors: Yukitoshi Kubota, Hidetoshi Wada, Yoshiyuki Nobuoka
-
Patent number: 5939185Abstract: A bearing material of silicon carbide particularly useful for application in the hot water field is provided having improved corrosion resistance under increased thermal stresses wherein the bearing material is characterized by a predominantly course-grained silicon carbide matrix of pressureless sintered silicon carbide having a biamodal grain sized distribution wherein the biomodal grain size distribution is formed by from 50 to 90% by volume of prismatic, tabular, silicon carbide crystallites having a length of from 100 to 1500 .mu.m and from 10 to 50% by volume of prismatic tabular silicon carbide crystallites having a length of from 5 to <100 .mu.m.Type: GrantFiled: October 29, 1997Date of Patent: August 17, 1999Assignee: Elektroschmelzwerk Kempten GmbHInventors: Jochen Greim, Hubert Thaler, Michael Fundus
-
Patent number: 5932506Abstract: A refractory castable comprised of:about 45% to about 75% by weight high alumina grain;about 2% to about 35% by weight silicon carbide;about 1% to about 8% by weight carbon;about 1% to about 8% by weight calcium aluminate cement; andabout 1% to about 10% by weight fine magnesium aluminate spinel,the spinel having a grain size of less than about 150 .mu.m (100 Tyler mesh) and being comprised of about 10% to about 33% by weight magnesium oxide (MgO) and about 67% to about 90% by weight alumina (Al.sub.2 O.sub.3).Type: GrantFiled: February 23, 1998Date of Patent: August 3, 1999Inventor: Jeffrey E. Bogan
-
Patent number: 5906799Abstract: The present invention is a reactor for the hydrogenation of chlorosilanes at temperatures above about 600.degree. C. The reactor comprises one or more of the following improvements: (1) a reaction chamber formed from a silicon carbide coated carbon fiber composite, (2) a heating element formed from a silicon carbide coated carbon fiber composite, and (3) one or more silicon nitride insulators electrically insulating the heating element.Type: GrantFiled: June 1, 1992Date of Patent: May 25, 1999Assignee: Hemlock Semiconductor CorporationInventors: Richard Anthony Burgie, Eric Michael Fleming
-
Patent number: 5902760Abstract: This invention is a process for making crack-free silicon carbide components wherein the level of free silica in the raw batch is controlled.Type: GrantFiled: September 10, 1997Date of Patent: May 11, 1999Assignee: Saint-Gobain/Norton Industrial Ceramics CorporationInventors: Stephen Dynan, Jack Shindle, John Vayda
-
Patent number: 5894066Abstract: Ceramic composites of silicon carbide (SiC) grains and boron carbide (B.s4 C) grains which are uniformly coated with SiC are produced by reacting stoichiometric mixtures of silicon boride (SiB.sub.4, SiB.sub.6) and carbon (graphite or carbon black) in situ.Type: GrantFiled: January 12, 1998Date of Patent: April 13, 1999Assignee: The United States of America as represented by the Secretary of the NavyInventors: Inna G. Talmy, James A. Zaykoski
-
Patent number: 5856251Abstract: Castable refractory for a slide gate plate is mainly formed of alumina raw material and amorphous carbon raw material of 2 to 15 wt %, and contains silicon carbide and/or boron carbide, the total content thereof being equal to 0.5 to 10 wt % (the content of boron carbide is equal to or less than 3 wt %, and when the content of boron carbide is less than 0.5 wt %, silicon carbide is set to 3 wt % or more), 2 to 10 wt % magnesia of 1 mm or less in particle size, 0.2 to 3 wt % silica fine powder of 5 micrometers or less in particle size, and 0.1 to 5 wt % salt of condensate of formalin and aromatic sulfonate.Type: GrantFiled: June 9, 1997Date of Patent: January 5, 1999Assignee: Toshiba Ceramics Co., Ltd.Inventors: Hisahiro Teranishi, Isao Imai, Toshihiro Indou
-
Patent number: 5840639Abstract: A method for producing a crack-free recrystallized silicon carbide body, icluding the steps of:a) providing a raw powder batch including:i) at least 40 w/o fine fraction having a particle size of less than 10 microns, the fine grain fraction including silicon carbide and fine free carbon, wherein the fine free carbon is present in an amount of at least 0.10 w/o of the raw batch, the fine free carbon having a surface area of at least 10 m.sup.2 /g,ii) at least 40 w/o coarse grain fraction having a particle size of at least 30 microns, the coarse grain fraction including silicon carbide and coarse free carbon, wherein the coarse free carbon is present in an amount of at least 0.10 w/o of the coarse grain fraction,the raw batch having a total silica content of at least 0.5 w/o,the raw batch having a total silicon carbide content of at least 96 w/o,b) forming the raw batch into a green body, andc) recrystallizing the green body to provide a recrystallized silicon carbide body having a density of between 2.Type: GrantFiled: September 10, 1997Date of Patent: November 24, 1998Assignee: Saint-Gobain/Norton Industrial Ceramics CorporationInventors: Jack Shindle, Stephen Dynan, John Vayda
-
Patent number: 5837631Abstract: The invention relates to a microporous carbon-bound molded SiC body with granular SiC, secondarily formed SiC and a secondarily formed silicon compound, for use as inwall brick for lining a blast furnace as well as for use as susceptor for heating ceramic, electrically non-conductive molded bodies, inorganic melts, glasses and slags.Type: GrantFiled: November 8, 1996Date of Patent: November 17, 1998Assignee: Didier-Werke AGInventors: Ingo Elstner, Daniel Grimm, Rudolf Hebel, Klaus Santowski
-
Patent number: 5834387Abstract: Silicon carbide sintered bodies having controlled porosity in the range of about 2 to 12 vol %, in which the pores are generally spherical and about 50 to 500 microns in diameter, are prepared from raw batches containing a polymer fugitive. Sintered bodies in the form of mechanical seal members exhibit lower power consumption at low PV and, in addition, lower wear rates at high PV in comparison to commercially available silicon carbide seal members.Type: GrantFiled: July 25, 1997Date of Patent: November 10, 1998Assignee: The Carborundum CompanyInventors: Ramesh Divakar, Sai-Kwing Lau
-
Patent number: 5786075Abstract: Provided is a heat sink which has excellent processability and is economical, even though it employs diamond, as well as, a process for producing the same. The heat sink is molded using a composition obtained by adding a diamond powder of 0.1 to 100 .mu.m high-purity diamond particles to cemented carbide primarily of WC and a balance of at least one metal selected from Co, Ni and Fe along with impurities. The proportion of the diamond powder admixed relative to the cemented carbide is preferably 5 to 90%, and the diamond heat sink is produced by sintering the particulate mixture of diamond, WC, Co, etc. at a temperature of 1200.degree. to 1500.degree. C. under a pressure of 3 to 6 GPa.Type: GrantFiled: March 28, 1995Date of Patent: July 28, 1998Assignee: Fuji Die Co., Ltd.Inventors: Minoru Mishuku, Osamu Terada
-
Patent number: 5785922Abstract: A composite sintered body of silicon carbide and silicon nitride having a nano-composite structure in which fine SiC particles are dispersed in Si.sub.3 N.sub.4 particles and grain boundaries and fine Si.sub.3 N.sub.4 particles are dispersed in SiC particles is produced by (a) adding at least one sintering aid, boron and carbon to a mixed powder of silicon carbide and silicon nitride to form a green body, the sintering aid being (i) Al.sub.2 O.sub.3 or AlN and/or (ii) at least one oxide of an element selected from Groups 3A and 4A of the Periodic Table, and (b) sintering the green body by HIP or by a high-temperature normal sintering method.Type: GrantFiled: November 16, 1995Date of Patent: July 28, 1998Assignee: Honda Giken Kogyo Kabushiki KaishaInventors: Yoshikatsu Higuchi, Kazumi Miyake
-
Patent number: 5772754Abstract: An electron beam of more than 1.times.10.sup.19 e/cm.sup.2 .multidot.sec is irradiated to metastable metal oxide particles such as .theta.-Al.sub.2 O.sub.3 particles or the like disposed on an amorphous carbon film. A phase transformation or the like of the metastable metal oxide particles is occurred by the electron beam irradiation. Thus, stable metal oxide ultrafine particles such as an .alpha.-Al.sub.2 O.sub.3 ultrafine particle 2 whose diameter is more tiny than the metastable metal oxide particles used, and a metal ultrafine particle composed of an oxide such as Al ultrafine particles are produced.Type: GrantFiled: February 7, 1996Date of Patent: June 30, 1998Assignees: Research Development Corporation of Japan, Shun-ichiro TanakaInventors: Shun-ichiro Tanaka, Bing She Xu
-
Patent number: 5707065Abstract: Mechanically strong and reduced friction porous silicon carbide sintered shaped articles, well adapted for the production, e.g., of leaktight mechanical packings and rotating bearing seals, have a total pore volume ranging from 4% to 18% thereof, the pores of which having an average diameter of the spherical closed pores ranging from 40 to 200 .mu.m.Type: GrantFiled: December 12, 1996Date of Patent: January 13, 1998Assignee: Ceramiques et Composites S.A.Inventors: Olivier Azema, Michel Bougoin
-
Patent number: 5707567Abstract: A self-sintered silicon carbide/carbon-graphite composite material having interconnected pores which may be impregnated, and a raw batch and process for producing the composite material, is provided. The composite material comprises a densified, self-sintered matrix of silicon carbide, carbon-graphite inclusions and small amounts of any residual sintering aids, such as boron and free carbon, and has interconnected pores which may be impregnated with resin, carbon, TEFLON, (polyetrafluoroethylene) metal or other compounds or materials selected for their particular properties to achieve desired tribological characteristics for a specific application. The composite material is produced from a raw batch which includes silicon carbide, sintering aids, a temporary filler and coated graphite particles. The raw batch is then molded/shaped into a green body and heated to carbonize any carbonizable materials and to decompose and volatilize the organic filler to form a matrix of interconnected pores.Type: GrantFiled: June 2, 1995Date of Patent: January 13, 1998Assignee: The Morgan Crucible Company PLCInventor: Mark E. Pfaff
-
Patent number: 5702997Abstract: This invention relates to a method for producing a crack-free sintered silicon carbide body, comprising the steps of:a) providing a raw powder batch comprising:i) at least 40 w/o fine grain fraction having a particle size of less than 10 microns, the fine grain fraction comprising silicon carbide,ii) at least 40 w/o coarse grain fraction having a particle size of at least 30 microns, the coarse grain fraction comprising silicon carbide and less than 0.10 w/o free carbon,the raw batch having a total silica content of at least 0.5 w/o,the raw batch having a total silicon carbide content of at least 96 w/o,b) forming the raw batch into a green body, andc) recrystallizing the green body to provide a recrystallized silicon carbide body having a density of between 2.0 g/cc and 2.8 g/cc.Type: GrantFiled: October 4, 1996Date of Patent: December 30, 1997Assignee: Saint-Gobain/Norton Industrial Ceramics Corp.Inventors: Stephen Dynan, Jack Shindle, John Vayda
-
Patent number: 5667548Abstract: The invention concerns the field of slip casting for producing green compacts. The disadvantage of state-of-the art slip casting is among others the need for removing the water through porous molds, the resulting shrinkage and the tendency of the green compact to form shrinkage cracks. These disadvantages are eliminated by internally coagulating by compression the double layer of solid slip particles, so that the green compact may be solidified without the need for removing the water.Type: GrantFiled: February 3, 1995Date of Patent: September 16, 1997Assignees: Thomas Graule, Ludwig J. GaucklerInventors: Thomas Graule, Ludwig J. Gauckler, Felix Baader