Silicon Carbide Patents (Class 501/88)
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Patent number: 6736875Abstract: Composite cordierite honeycomb structures especially suitable for diesel exhaust filtration applications comprise a non-oxide polycrystalline phase constituting 10-70% by weight, with the remainder of the ceramic material constituting a cordierite phase, the non-oxide polycrystalline phase being selected from the group consisting of carbides, nitrides, and borides. Preferably the non-oxide phase is either polycrystalline silicon carbide or polycrystalline silicon nitride and has a particle aspect ratio of less than 3. Inventive ceramic bodies are porous with an open porosity of at least 30%, preferably between 40% and 60%, and a median pore size of at least 5 micrometers, more preferably greater than 8 micrometers and less than 12 micrometers.Type: GrantFiled: December 13, 2001Date of Patent: May 18, 2004Assignee: Corning IncorporatedInventors: Kishor P. Gadkaree, Yanxia Lu, Joseph F. Mach, Christopher J. Warren, Yuming Xie
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Patent number: 6733736Abstract: A method of producing a silicon carbide powder comprising sintering a mixture containing at least a silicon source and a carbon source wherein the carbon source is a xylene-based resin. Preferable are an embodiment in which the above-mentioned silicon source is an alkoxysilane compound, an embodiment in which the above-mentioned alkoxysilane compound is selected from an ethoxysilane oligomer and an ethoxysilane polymer, an embodiment in which the above-mentioned mixture is obtained by adding an acid to a silicon source, then, by adding a carbon source, and other embodiments. A silicon carbide powder produced by the above-mentioned method of producing a silicon carbide powder wherein the nitrogen content is 100 ppm or less is preferable. A sintered silicon carbide obtained by sintering the above-mentioned silicon carbide powder wherein the volume resistivity is 1×100 &OHgr;·cm or more.Type: GrantFiled: April 25, 2002Date of Patent: May 11, 2004Assignee: Bridgestone CorporationInventors: Masashi Otsuki, Shigeki Endo
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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
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Patent number: 6709999Abstract: A molded part of a ceramic material derived from polymers includes a composite body of a single-phase or multi-phase, amorphous, partially crystalline or crystalline matrix of silicon carbide (SiC), silicon nitride (Si3N4), silicon dioxide (SiO2) or mixtures thereof. The matrix contains graphite inclusions and the density of the ceramic material is at least 85% of the theoretical value. The molded part is produced by subjecting a mixture formed of a polymer component in an amount of 30 to 80 wt. % referred to the total weight of the mixture, fillers in an amount of 0 to 30 wt. % and graphite in an amount of 10 to 70 wt. %, to a forming process with heating to effect crosslinking of the polymer components, followed by a pyrolysis process. In particular, the molded parts are produced from polymers of the group including polysilanes, polysiloxanes, polysilazanes or polycarbosilanes. A process for producing ceramic molded parts and a sliding element having a molded part are also provided.Type: GrantFiled: June 18, 2001Date of Patent: March 23, 2004Assignee: SGL Carbon AGInventors: Peter Greil, Oliver Dernovsek, Hans-Michael Güther, Ulrich Wislsperger
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Patent number: 6696514Abstract: A process for making in-situ carbide in the form of particulate, whiskers and fibres in an inorganic composite matrix, which comprises, dissolving 38 to 73.5 Wt % of phenolic resin in an organic solvent to obtain a phenolic resin solution, adding 4.2-11.0 Wt %—of a curing agent optionally adding 9.4-12 Wt % of silicon carbide powder to obtain a resin mix followed by impregnating 1.6-6.5 Wt % of natural fibre with the said resin mix dried at 60°-70° C. for a period in the range of 1-5 hrs. to obtain a dough in the form of a composite plate sheet, drying the said composite plate or sheet at a temperature in the range of 70°-90° C. for a time period in the range of 1-2 hrs., drying the composite plate or sheet, heat treating the dried composite plate or sheet at a temperature in the range of —150°-200° C. for a period in the range of 1-2.5 hrs., impregnating the resultant composite plate or sheet with 10.Type: GrantFiled: December 19, 2002Date of Patent: February 24, 2004Assignee: Council of Scientific & Industrial ResearchInventors: Kalyan Kumar Phani, Asok Kumar De, Nripati Ranjan Bose, Sankar Ghatak
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Patent number: 6696144Abstract: The present invention is a low density hybrid airfoil comprising a temperature resistant exterior layer and a tough, high impact resistant interior layer. Specifically, the airfoil comprises a monolithic ceramic exterior layer and a fiber reinforced ceramic matrix composite interior layer. Both the monolithic ceramic and fiber reinforced ceramic matrix composite are low density materials. Additionally, the monolithic ceramic is a high temperature resistant material, and the fiber reinforced ceramic matrix composite is a relatively high impact resistant structure. Encapsulating the airfoil with a temperature resistant exterior layer protects the airfoil in a high temperature environment, and supporting the airfoil with a high impact resistant, fiber reinforced ceramic matrix composite improves the overall impact resistance of the airfoil thereby resulting in a tough, high temperature resistant, low density airfoil.Type: GrantFiled: April 24, 2002Date of Patent: February 24, 2004Assignee: United Technologies CorporationInventors: John E. Holowczak, Karl M. Prewo, Jayant S. Sabnis, William K. Tredway
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Patent number: 6695984Abstract: The present invention provides: a fabrication method of a silicon carbide sintered body, including a step of fabricating a mixed powder slurry by dissolving or dispersing silicon carbide powder, at least one organic material composed of a nitrogen source, and at least one organic material composed of a carbon source or carbon powder in a solvent, a step of fabricating a green body by pouring the mixed powder slurry into a mold and drying and a step of filling pores in the green body by immersing the green body in high purity metallic silicon that has been heated to 1450 to 1700° C. in a vacuum atmosphere or inert gas atmosphere and melted, and generating silicon carbide by reacting silicon sucked up into the pores in the green body by capillary action with free carbon in the green body; and a silicon carbide sintered body obtained by a reaction sintering method, having a density of 2.90 g/cm3 or more and a volume resistivity of 100 &OHgr;·cm or less, and containing nitrogen at 150 ppm or more.Type: GrantFiled: January 31, 2001Date of Patent: February 24, 2004Assignee: Bridgestone CorporationInventors: Fumio Odaka, Yoshitomo Takahashi
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Publication number: 20040029704Abstract: Production processes of an inorganic fiber-bonded ceramic component comprising inorganic fibers mainly comprising Si, M, C and O, an inorganic substance mainly comprising Si and O and boundary layers comprising carbon as a main component; and an inorganic fiber-bonded ceramic component comprising inorganic fibers which are composed mainly of a sintered structure of SiC and contain specific metal atoms and boundary layers composed mainly of carbon, wherein a preliminary shaped material is set in a carbon die, covered with a carbon powder and then hot-pressed to load a pseudo-isotropic pressure on the preliminary shaped material; and a highly heat-resistant inorganic fiber-bonded ceramic component almost free from the occurrence of peelings of surface fibers or delamination, wherein fibers are aligned in a surface shape.Type: ApplicationFiled: August 6, 2003Publication date: February 12, 2004Inventors: Shinij Kajii, Kenji Matsunaga, Toshihiko Hogami, Mitsuhiko Sato
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Patent number: 6689202Abstract: Blocks of material are prepared in a variety of shapes and sizes to be used in the fabrication of models for dental restorations. The material comprises a partially sintered ceramic material. The blocks are used to manufacture molds using CAD/CAM methods and equipment. The molds are useful in the manufacture of dental restorations using ceramics, metals, alloys, or powders thereof, and composite materials. The models milled from the blanks may be used to manufacture a variety of dental restorations including, but not limited to, crowns, bridges, space maintainers, tooth replacement appliances, orthodontic retainers, dentures, posts, jackets, inlays, onlays, facings, veneers, facets, implants, abutments, splints, partial crowns, teeth, cylinders, pins, and connectors.Type: GrantFiled: July 13, 2001Date of Patent: February 10, 2004Assignee: Jeneric/Pentron IncorporatedInventor: Carlino Panzera
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Publication number: 20040023788Abstract: 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.Type: ApplicationFiled: July 30, 2002Publication date: February 5, 2004Applicant: Kennametal Inc.Inventors: Pankaj K. Mehrotra, Shanghua Wu
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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
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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
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Patent number: 6663776Abstract: There is provided an improved ceramic foam filter for use in filtering molten metals, metal prepared from a ceramic slurry containing silicon carbide, a colloidal silica binder and at least 10 percent of fumed silica. The filter has enhanced strength properties.Type: GrantFiled: September 27, 2002Date of Patent: December 16, 2003Assignee: Selee CorporationInventors: William Isaac Hoffman, Rudolph A. Olson, III
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Publication number: 20030207749Abstract: The present invention relates to shaped bodies made of fiber-reinforced ceramic composites and comprising a core zone and at least one covering layer which has a coefficient of thermal expansion which is higher than that of the core zone. The covering layer is an SiC-rich covering layer and is divided into segments which are separated from the adjacent segments by gaps or bridging zones of a material which is different from the material of the segments. The invention also relates to a process for producing such shaped bodies by infiltration of an intermediate body with molten silicon and their use for friction disks, in vehicle construction or as protective plates.Type: ApplicationFiled: November 22, 2002Publication date: November 6, 2003Inventors: Moritz Bauer, Nadine Hander, Andreas Kienzle, Rainer Zimmermann-Chopin
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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
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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
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Patent number: 6627169Abstract: A high purity silicon carbide powder, a production method thereof, and a high purity silicon carbide sintered body are provided. The silicon carbide powder contains impurity elements, each of the impurity elements being contained in an amount of at most 0.01 ppm; the production method of silicon carbide powder includes a burning step, in which amounts of carbon monoxide generated during burning are detected and temperature adjustments are controlled in accordance with the detected amounts, and a heat treatment step, in which silicon carbide powder obtained in the burning step is heat-treated in a vacuum atmosphere; and the silicon carbide sintered body is formed by sintering silicon carbide powder.Type: GrantFiled: May 23, 2000Date of Patent: September 30, 2003Assignee: Bridgestone CorporationInventors: Michio Itoh, Shigeki Endo
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Publication number: 20030180579Abstract: Improved silicon carbide composites made by an infiltration process feature a metal phase in addition to any residual silicon phase. Not only are properties such as mechanical toughness improved, but the infiltrant can be so engineered as to have much diminished amounts of expansion upon solidification, thereby enhancing net-shape-making capabilities. Further, multi-component infiltrant materials may have a lower liquidus temperature than pure silicon, thereby providing the practitioner greater control over the infiltration process. In particular, the infiltration may be conducted at the lower temperatures, where low-cost but effective bedding or barrier materials can terminate the infiltration process once the infiltrant has migrated through the permeable mass up to the boundary between the mass and the bedding material.Type: ApplicationFiled: January 3, 2003Publication date: September 25, 2003Inventors: W. Michael Waggoner, Barry R. Rossing, Michael A. Richmond, Michael K. Aghajanian, Allyn L. McCormick
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Publication number: 20030167969Abstract: Ceramic friction linings comprising a material consisting essentially of metal oxides which are present in the form of a sintered ceramic or in the form of ceramic particles bound by carbon and/or carbides, processes for producing them and their use in combination with ceramic friction bodies, in particular for high-performance brakesType: ApplicationFiled: March 5, 2003Publication date: September 11, 2003Inventors: Ronald Huener, Moritz Bauer, Peter Winkelmann
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Publication number: 20030162647Abstract: Material from a fibre composite ceramic, constructed fromType: ApplicationFiled: February 6, 2003Publication date: August 28, 2003Inventor: August Muhlratzer
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Publication number: 20030151152Abstract: Exemplary silicon carbide ceramic bodies are produced according to the invention. An exemplary ceramic body includes silicon carbide in major amounts and an organic gelation agent in a minor amount. An exemplary ceramic body exhibits sufficient density and hardness to function as body armor.Type: ApplicationFiled: February 8, 2002Publication date: August 14, 2003Applicant: CoorsTek, Inc.Inventors: Noah Nichelson, Gary Ross
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Patent number: 6605556Abstract: 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.Type: GrantFiled: June 7, 1995Date of Patent: August 12, 2003Assignee: United Technologies CorporationInventor: Sudhangshu Bose
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Publication number: 20030134736Abstract: A transition metal-containing ceramic made by the process comprising the step of pyrolyzing an organometallic linear polymer containing at least one metallocenylene unit, at least one silyl or siloxyl unit, and at least one acetylene unit to form a ceramic; where the ceramic has a ceramic yield of at least about 75% by weight. A transition metal-containing ceramic made by the process comprising the steps of: forming an organometallic linear polymer containing at least one metallocenylene, at least one silyl or siloxyl unit, and at least one acetylene unit; crosslinking said linear polymer through the acetylene units, thereby forming a thermoset; and pyrolyzing said thermoset to form a ceramic; where the ceramic has a ceramic yield of at least about 75% by weight.Type: ApplicationFiled: November 4, 2002Publication date: July 17, 2003Inventor: Teddy M. Keller
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Patent number: 6589448Abstract: A ceramic bearing ball in which at least a portion of a constituent ceramic is formed of an electrically conductive inorganic compound phase, whereby a proper electrical conductivity is imparted to the ceramic. Thus, electrifying of a bearing ball is prevented or effectively suppressed. This prevents the problem involved in production of balls of small diameter wherein such balls adhere to an apparatus (e.g., a container) during production thereof, thus hindering smooth progress of the production process. In addition, when ceramic balls are used in precision electronic equipment, such as a hard disk drive of a computer, which is operated at high rotational speed, adhesion of foreign substance due to electrification of the balls, and resultant generation of abnormal noise or vibration can be prevented or effectively suppressed.Type: GrantFiled: April 10, 2001Date of Patent: July 8, 2003Assignee: NGK Spark Plug Co., Ltd.Inventors: Tomonori Niwa, Tetsuji Yogo
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Patent number: 6582650Abstract: An oxide-containing organosilicon polymer containing 1 to 45% by weight of metal oxide particles, an oxide-containing silicon-carbide-based inorganic fiber obtained by using the above organosilicon polymer as a raw material and having excellent oxidation resistance, in particular excellent oxidation resistance in a high temperature oxidizing atmosphere containing moisture, a crystalline silicon-carbide-based inorganic fiber having a calcined structure of SiC and production processes of these.Type: GrantFiled: July 20, 2001Date of Patent: June 24, 2003Assignee: Ube Industries, Ltd.Inventors: Kiyoshi Kumagawa, Masaki Shibuya, Michiyuki Suzuki, Hiroyuki Yamaoka
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Publication number: 20030114294Abstract: The invention relates to a process for the production of ceramic bearing components in which a mixture of a metallo-organic compound and a chemically reactive filling substance is subjected to a pyrolysis reaction and the resulting product.Type: ApplicationFiled: November 8, 2002Publication date: June 19, 2003Inventor: Jurgen Gegner
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Publication number: 20030092557Abstract: A ceramic composite material, for example, a ceramic molded body or a layer obtained by pyrolysis of a starting mixture, containing at least one polymer precursor material and at least one filler, which has an average particle size of less than 200 nm. Such a composite material may be used, for example, for producing fibers, filters, catalyst support materials, ceramic sheathed-element glow plugs, metal-containing reactive composite materials, porous protective shells for sensors, ceramic or partially ceramic coatings or microstructured ceramic components.Type: ApplicationFiled: October 29, 2002Publication date: May 15, 2003Inventors: Wilfried Aichele, Wolfgang Dressler, Christof Rau, Volker Knoblauch, Alexander Kloncynski, Horst Boeder
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Patent number: 6561793Abstract: A method of forming a porous ceramic matrix for use in an infrared heating unit comprises the steps of mixing ceramic fibers, organic binders and particulate material capable of infrared emissivity with an ionic wetting agent to form a moldable ceramic mixture, and molding the mixture to a desired shape. A ceramic matrix with infrared emissivity particles substantially uniformly distributed through the matrix is formed which results in a high intensity, high thermal efficiency matrix for use in an infrared heater. In a further aspect, the matrix can be formed using at least two different compositions of ceramic fibers each composition having a different melting temperature. During operation of the matrix in a heater unit over normal operating temperatures, melting and re-crystallization of the ceramic fibers with the lower melting temperature occurs resulting in the creation of crystalline bond regions between the two fiber compositions.Type: GrantFiled: August 14, 2000Date of Patent: May 13, 2003Assignee: Honeywell ASCa Inc.Inventor: Dave Narasimhan
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Patent number: 6562745Abstract: This invention relates to an aging resistant SiC igniter having a second layer of recrystallized SiC within the body.Type: GrantFiled: July 24, 2001Date of Patent: May 13, 2003Assignee: Saint-Gobain Ceramics and Plastics, Inc.Inventors: Craig A. Willkens, Normand P. Arsenault, James Olson, Roger Lin
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Publication number: 20030087748Abstract: A long-lived cleaning vessel for ultrasonic cleaning is provided which is easily manufactured and is also easy to handle due to a simple structure thereof, and has excellent durability, mechanical strength, and corrosion resistance. A cleaning vessel 1 of the present invention includes a layer of silicon carbide sintered body 3 which propagates ultrasonic waves. Further, a silicon carbide sintered body is provided which can be applied to components for semiconductor production apparatuses, components for electronic information equipment, and various structural components for vacuum devices and the like, and which can particularly suitably be used as an ultrasonic resonance plate or an ultrasonic diaphragm, and can be easily processed, and further which can be made thinner while maintaining sufficient mechanical strength. The silicon carbide sintered body can propagate ultrasonic waves and an acoustic velocity of ultrasonic waves propagated therethrough is 4000 to 20000 m/s.Type: ApplicationFiled: November 14, 2002Publication date: May 8, 2003Applicant: BRIDGESTONE CORPORATIONInventors: Masashi Otsuki, Shigeki Endo, Yuka Murakawa
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Patent number: 6558821Abstract: In ceramic sinter consisting of at least one kind selected from a group consisting of silicon nitride, zirconia, silicon carbide, cermet, SIALON, aluminum nitride and alumina, wear resistant member and electronic component member using thereof, skewness at a contact surface of the ceramic sinter is set at −2 or more and 0 or less, a depth of a micro-crack is set at 5 &mgr;m or less, and in the depth of up to 500 &mgr;m from the surface an area that pores occupy does not exceed 5%. The ceramic sinter as described above can suppress wear of the opponent member. Further, in such ceramic sinter, bonding strength with an element or a metal plate can be heightened to enable to suppress peeling. The electronic components of high reliability can be fabricated accordingly. The present wear resistant member is suitable for sliding member that is used in portions where wear is particularly remarkable.Type: GrantFiled: March 17, 2000Date of Patent: May 6, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Katsuhiro Shinosawa, Hiroyasu Ohta, Mineyuki Yamaga
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Publication number: 20030072930Abstract: An object of the present invention is to provide a ceramic structure for improving the resistance against a corrosive substance and to diffuse and supply a fluid over a larger area of the structure. A ceramic laminated article 6 has a ceramic sintered body 1, and a ceramic film 3 provided on the sintered body 1 by means of chemical vapor deposition. A hollow 5 surrounded by the sintered body 1 and film 3, and communicating holes 1d, 4 communicated with the hollow 5 and the outside are formed in the article 6. A filling material 2 are filled in the recess 1c of the sintered body 1 and the holes 1d, 4 are formed. The thus obtained assembly 7 is heat treated to dissipate and remove the filling material 2 through the communicating holes 1d and 4, so that the recess 1c is left as the hollow 5.Type: ApplicationFiled: September 23, 2002Publication date: April 17, 2003Applicant: NGK Insulators, Ltd.Inventors: Hirotake Yamada, Toshio Oda, Hiromichi Kobayashi
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Patent number: 6548586Abstract: A composition useful for making in-situ silicon carbide whiskers and fibers in an inorganic composite matrix selected from silicon carbide carbon and carbon composite matrix, wherein the said composition comprises: Natural Fiber (1.6-6.5 Wt %); TetraEthyl Orthosilicate (10.4-42 Wt %); Phenolic Resin (38-73.5 Wt %); Curing agent (4.2-11 Wt %); Optionally, Silicon Carbide (9.4-12 Wt %); Organic Solvent (requisite amount to dissolve the Phenolic resin). The fiber preferably is a natural fiber selected from the group consisting of jute, sisal, hem and other natural fiber having cellulosic or hemicellulosic constituent at its backbone. The curing agent preferably is selected from hexamine, para toluenesulphonic acid and para formaldehyde, most preferably hexamine. The molecular weight of phenolic resin preferably is in the range of 450-700, and the organic solvent preferably is selected from methanol, toluene and benzene.Type: GrantFiled: February 22, 2001Date of Patent: April 15, 2003Assignee: Council of Scientific & Industrial ResearchInventors: Kalyan Kumar Phani, Asok Kumar De, Nripati Ranjan Bose, Sankar Ghatak
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Publication number: 20030050178Abstract: The invention comprises a self-lubricating ceramic composite characterized as having a low porosity derived from a mixture of at least one ceramic powder preferably selected from the group consisting of silicon nitride, silicon carbide, zirconia, alumina, zirconium nitride, tungsten carbide, and titanium carbide; a cemetitious binder, effective amounts of at least one metal silicide, and at least one metal oxide. The ceramic powder mixture can be slurried with sufficient amounts of water and subsequently subjected to pressures of about 6.0 to 7.0 MPa in a mold at temperatures of about 125° to 175° C. to form a self-lubricating ceramic composite capable of maintaining hot-hardness temperatures above 750° C. These self-lubricating ceramic composites are particularly useful in the manufacture of high-performance turbine engines, including engine parts, bearings, gears, rotors and in other areas where high-heat lubricating properties of the ceramic composite are required.Type: ApplicationFiled: September 7, 2001Publication date: March 13, 2003Inventors: Vinod S. Agarwala, Alfeo A. Conte
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Patent number: 6527092Abstract: A method for the production of brake discs having friction areas made of ceramic materials, in particular composite materials, includes placing at least one ceramic portion in a diecasting mold and joining the ceramic portion with molten metals by casting under pressure into a rotationally symmetrical body which contains at least one ceramic (composite) segment that is disposed symmetrically relative to the axis of rotation of the metal body and juts out over at least one surface of the metal body perpendicular to the axis. A brake disc produced according to the method is also provided.Type: GrantFiled: February 26, 2001Date of Patent: March 4, 2003Assignee: SGL Carbon AGInventors: Udo Gruber, Michael Heine, Andreas Kienzle
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Publication number: 20030036471Abstract: An opaque, low resistivity silicon carbide and a method of making the opaque, low resistivity silicon carbide. The opaque, low resistivity silicon carbide is doped with a sufficient amount of nitrogen to provide the desired properties of the silicon carbide. The opaque, low resistivity silicon carbide is a free-standing bulk material that may be machined to form furniture used for holding semi-conductor wafers during processing of the wafers. The opaque, low resistivity silicon carbide is opaque at wavelengths of light where semi-conductor wafers are processed. Such opaqueness provides for improved semi-conductor wafer manufacturing. Edge rings fashioned from the opaque, low resistivity silicon carbide can be employed in RTP chambers.Type: ApplicationFiled: June 6, 2002Publication date: February 20, 2003Applicant: Shipley Company, L.L.C.Inventors: Jitendra S. Goela, Michael A. Pickering
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Patent number: 6507481Abstract: The electronic component of the present invention includes a case having an opening, an electronic component element and electrolytic solution disposed in the case, and a sealing member disposed so as to seal the opening. The sealing member has elasticity and is formed of a cross-linked structure of compound. The compound contains butyl rubber polymer as main component, phenol-based additive, and silane-based additive. Accordingly, the sealing member is improved in air-tightness, and the volatilization of the electrolytic solution becomes lessened. Further, an electronic component having such sealing member ensures excellent mounting ability. As a result, it is possible to obtain an electronic component capable of assuring excellent reliability for a long period of time even in a high temperature atmosphere and under high-temperature high humidity conditions.Type: GrantFiled: January 8, 2002Date of Patent: January 14, 2003Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Koichiro Minato, Hiroshi Kurimoto, Junji Yamane
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Publication number: 20030004050Abstract: A method is provided for producing a fiber-reinforced material which is composed, at least in a region of a surface layer, of a ceramic composite and has carbon-containing fibers reaction-bonded to a matrix containing the elements Si and C. In particular a method of producing fiber-reinforced silicon carbide is provided in which a structure of a matrix contains cracks and/or pores, at least at ambient temperature, because of a high thermal expansion coefficient compared with that of the fibers. Metals are selectively electrodeposited in the open pores and cracks of the matrix and, in particular, in a region of the electrically conductive reinforcing fibers. As a result, the open pores and cracks are filled and, in addition, metallic top layers are optionally formed that are firmly keyed to the ceramic composite and that may serve as an interlayer for glass top layers or ceramic top layers.Type: ApplicationFiled: June 25, 2002Publication date: January 2, 2003Inventors: Martin Christ, Michael Heine, Andres Kienzle, Rainer Zimmermann-Chopin
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Publication number: 20020198095Abstract: 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.Type: ApplicationFiled: June 20, 2001Publication date: December 26, 2002Inventors: Tai-ll Mah, Triplicane A. Parthasarathy, Michael K. Cinibulk
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Publication number: 20020189496Abstract: Monazite or xenotime-based blanket coatings that stiffen ceramic fabrics without causing embrittlement at temperatures of at least as high as 2400° F. are provided. Methods for making the coatings are also provided. The methods comprise the synthesis of high purity, monazite and xenotime powders with the stoichiometric ratio of metal to phosphorous of about 1:1.Type: ApplicationFiled: June 18, 2001Publication date: December 19, 2002Inventors: Janet B. Davis, David B. Marshall, Peter Ernest David Morgan, Kris Shigeko Oka
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Patent number: 6495483Abstract: Transition metal-containing ceramic or carbonaeous material are formed from novel linear polymers containing a random distribution of repeating acetylenic units, organotransition metal complexes, siloxane, boron, silicon, and/or carborane-siloxane units. The precursor thermosets are formed by crosslinking of the linear polymers through the acetylenic units in the polymer backbone. The ceramics may also be formed directly by pyrolysis of the linear polymers. The preceramic polymers are potentially useful for fabricating ceramic fibers and composite materials having enhanced strength, hardness and toughness as well as superior mechanical, optical, electrical and/or magnetic properties.Type: GrantFiled: March 14, 1997Date of Patent: December 17, 2002Assignee: The United States of America as represented by the Secretary of the NavyInventors: Teddy M. Keller, Eric J. Houser
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Patent number: 6479174Abstract: A silicon carbide body includes polycrystals of silicon carbide, and has a purity of silicon carbide of not less than 99.9999 wt %, a relative density of not less than 99% and a ratio of silicon of not less than 70.12 wt %.Type: GrantFiled: April 6, 2000Date of Patent: November 12, 2002Assignee: NGK Insulators, Ltd.Inventors: Hirotake Yamada, Makoto Murai, Hiroshi Furukubo, Tsuneaki Ohashi
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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
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Publication number: 20020151428Abstract: The present invention provides a silicon/silicon carbide composite and having a high quality in avoiding warp or breakage and in a corrosion resistance, a durability, a heat shock resistance and particularly suitable used for semiconductor heat treatment member such as a dummy wafer or the like and a process for manufacturing a high purity silicon/silicon carbide composite containing a limited amount of carbon left without reaction.Type: ApplicationFiled: December 21, 2001Publication date: October 17, 2002Applicant: TOSHIBA CERAMICS CO., LTD.Inventors: Yushi Horiuchi, Masahiro Yamaguchi, Jianhui Li
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Publication number: 20020151427Abstract: Process for the manufacturing of ceramic-matrix composite layers resistant to very high temperatures, comprising the steps of: preparing the powders for the feeding of the deposition plant by wet mixing of the ceramics constituting the material in form of fine powders and atomizing the suspension in the presence of a hot air jet; and depositing by plasma thermal spraying with an inert gas flow and with a >30 kPa pressure in a deposition chamber. This process forms composite layers having a very high resistance, apt to be employed as coatings for vehicles, of the type destined to reenter Earth atmosphere from outer space and to be launched again therein.Type: ApplicationFiled: March 12, 2002Publication date: October 17, 2002Applicant: Centro Sviluppo Materiali S.p.A.Inventors: Mario Tului, Teodoro Valente
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Patent number: 6461989Abstract: A process is provided for forming a material comprising an M3X1Z2 phase comprising the steps of: (a) providing a mixture of (i) at least one transition metal species, (ii) at least one co-metal species selected from the group consisting of aluminum species, germanium species and silicon species, and (iii) at least one non-metal species selected from the group consisting of boron species, carbon species and nitrogen species; (b) heating said mixture to a temperature of about 1000° C. to about 1800° C., in an atmosphere within a substantially enclosed heating zone, for a time sufficient to form said M3X1Z2 phase; wherein the atmosphere has an O2 partial pressure of no greater than about 1×10−6 atm. The process provides a substantially single phase material comprising very little MZx-phase.Type: GrantFiled: December 22, 1999Date of Patent: October 8, 2002Assignees: Drexel University, Sandvik ABInventors: Tamer El-Raghy, Michel W. Barsoum, Mats Sundberg, Hans Pettersson
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Patent number: 6458732Abstract: A dry refractory composition having superior insulating value. The dry refractory composition also may have excellent resistance to molten metals and slags. The composition includes filler lightweight material, which may be selected from perlite, vermiculite, expanded shale, expanded fireclay, expanded alumina silica hollow spheres, bubble alumina, sintered porous alumina, alumina spinel insulating aggregate, calcium alumina insulating aggregate, expanded mulllite, cordierite, and anorthite, and matrix material, which may be selected from calcined alumina, fused alumina, sintered magnesia, fused magnesia, silica fume, fused silica, silicon carbide, boron carbide, titanium diboride, zirconium boride, boron nitride, aluminum nitride, silicon nitride, Sialon, titanium oxide, barium sulfate, zircon, a sillimanite group mineral, pyrophyllite, fireclay, carbon, and calcium fluoride.Type: GrantFiled: June 7, 1999Date of Patent: October 1, 2002Assignee: Allied Mineral Products, Inc.Inventors: Douglas K. Doza, John Y. Liu
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Publication number: 20020070485Abstract: It is an object of the present invention to provide a method for simply producing a high purity silicon carbide sintered body having no remaining metal silicon and excellent heat resistance. A method for producing a silicon carbide sintered body of the present invention comprises the steps of: preparing a slurry by dispersing silicon carbide powder in a solvent; forming a molded body by pouring the slurry into a mold and effecting calcination for the slurry in a vacuum atmosphere or in an inert gas atmosphere; and sealing pores within the calcined molded body by impregnating the pores with high purity metal silicon molten by heating, and allowing the high purity metal silicon and carbon contained in the molded body to react on each other in the pores so as to produce silicon carbide.Type: ApplicationFiled: August 30, 2001Publication date: June 13, 2002Applicant: Bridgestone CorporationInventors: Fumio Odaka, Kazuhiro Ushita, Yoshitomo Takahashi
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Patent number: 6403155Abstract: This invention is a high strength, thermal shock resistant, high purity siliconized silicon carbide material made from siliconizing a converted graphite SiC body having at least 71 vol % silicon carbide therein.Type: GrantFiled: December 21, 2000Date of Patent: June 11, 2002Assignee: Saint-Gobain Ceramics & Plastics, Inc.Inventors: Dominique Dubots, Andrew Haerle
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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