Utilizing Chemically Reactive Atmosphere Other Than Air, Per Se, During Sintering To Convert Precursor To Ceramic Material Patents (Class 264/646)
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Patent number: 12186807Abstract: A heterogeneous composite consisting of near-nano ceramic clusters dispersed within a ductile matrix. The composite is formed through the high temperature compaction of a starting powder consisting of a core of ceramic nanoparticles held together with metallic binder. This core is clad with a ductile metal such that when the final powder is consolidated, the ductile metal forms a tough, near-zero contiguity matrix. The material is consolidated using any means that will maintain its heterogeneous structure.Type: GrantFiled: November 22, 2022Date of Patent: January 7, 2025Assignee: POWDERMET, INC.Inventors: Mark Grogan, Brian Doud, Andrew Sherman
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Patent number: 11148197Abstract: A raw material for thixomolding includes a magnesium-based alloy powder which contains calcium in an amount of 0.2 mass % or more and 5 mass % or less and aluminum in an amount of 2.5 mass % or more and 12 mass % or less, wherein the magnesium-based alloy powder includes an oxide layer which has an average thickness of 30 nm or more and 100 nm or less and contains at least one of calcium and aluminum as an outermost layer. The average dendrite secondary arm spacing of crystal structures of the magnesium-based alloy powder is preferably 5 ?m or less.Type: GrantFiled: August 30, 2018Date of Patent: October 19, 2021Inventors: Yasutoshi Hideshima, Hidefumi Nakamura, Hiroyoshi Otaka
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Patent number: 9517940Abstract: Acicular mullite bodies are made in two-step firing process in which a green body is converted first to a fluorotopaz and then to acicular mullite. The bodies are contained within an enclosed region of the furnace. A flow of process gas is provided through the enclosed region during the fluorotopaz-forming step. The process gas is introduced into the enclosed region through multiple openings on at least one side of the enclosed region, and withdrawn through multiple openings on another side of the enclosed region. During the acicular mullite-forming step, a flow of purge gas is maintained in the exterior portion of the furnace. This purge gas may be removed by flowing it into the enclosed region of the furnace and out of the furnace from the enclosed region without re-entering the exterior portion for the furnace.Type: GrantFiled: June 21, 2012Date of Patent: December 13, 2016Assignee: Dow Global Technologies LLCInventors: Douglas D. Merrick, Kristina Platkowski, Janet M. Goss
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Publication number: 20150031153Abstract: A method of fabricating a sputtering target is provided. The method includes preparing a first powder material, wherein the first powder material includes tin oxide; preparing a mixture by mixing the first powder material and a second powder material, wherein the second powder material includes carbon; and fabricating the sputtering target by compressing and sintering the mixture simultaneously in a reducing atmosphere.Type: ApplicationFiled: March 24, 2014Publication date: January 29, 2015Applicant: Samsung Display Co., Ltd.Inventors: Sang-Wook Sin, Sun-Young Jung, Il-Sang Lee, Jin-Woo Park, Dong-Jin Kim
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Publication number: 20150014652Abstract: A method of fabricating a sputtering target, a sputtering target fabricated by the method, and an organic light-emitting display apparatus fabricated by using the sputtering target. The sputtering target may be used for forming a thin film encapsulation layer. The sputtering target includes tin oxide as a main component, and a copper fluoride compound as a dopant.Type: ApplicationFiled: February 28, 2014Publication date: January 15, 2015Applicant: SAMSUNG DISPLAY CO., LTD.Inventors: Su-Hyuk Choi, Hun Kim, Jin-Woo Park
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Publication number: 20140361471Abstract: A method of preparing and rapidly curing a composite material having a thin cross section. The composite material includes a mixture of solid particles, at least some of which are a material that reacts with CO2, such as a silicate, for example Wollastonite. The green material is prepared by mixing the solid components with a liquid such as water to form a slurry, and forming green bodies by placing the slurry in forms. The green bodies are reacted with CO2 to form cured composite materials having thin sections, in the range of 10 to 15 mm. Curing in periods of 6 hours has been demonstrated.Type: ApplicationFiled: June 4, 2014Publication date: December 11, 2014Applicant: SOLIDIA TECHNOLOGIES, INC.Inventors: Xudong Hu, Deepak Ravikumar, Devin Patten
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Publication number: 20140197353Abstract: The embodiments described herein pertain generally to graphene/ceramic nanocomposite powder including a matrix ceramic; and graphene dispersed in the matrix ceramic and a preparation method thereof, and a graphene/ceramic nanocomposite material including the graphene/ceramic nanocomposite powder and a preparation method thereof.Type: ApplicationFiled: January 22, 2014Publication date: July 17, 2014Applicant: KOREA ADVANCED INSTITUTE OF SCEINCE AND TECHNOLOGYInventors: Soonhyung Hong, Min Young Koo, Jaewon Hwang, Bin Lee
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Publication number: 20120308813Abstract: A temperature-resistant ceramic hybrid material has a matrix made of calcium silicate hydrate. Carbon is embedded in the matrix. The carbon is predominantly composed of graphite particles having an ordered graphitic lattice structure and the carbon makes up a weight fraction of up to 40%. The matrix is composed of tobermorite and/or xonotlite and can contain wollastonite rods and/or granular silicate. The size of the graphite particles is 0.01-3 mm. The hybrid material is especially suitable for casting devices for non-ferrous metals.Type: ApplicationFiled: January 14, 2011Publication date: December 6, 2012Applicant: CALISTHERM VERWALTUNGS GMBHInventors: Klaus Hoelscher, Tobias Hoelscher, Wolf Huettner, Axel Lengen, Hans-Juergen Schneider, Winfried Stellmach
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Publication number: 20120201736Abstract: A method of producing a silicon carbide molded item is provided. The method includes molding a curable silicone composition comprising a silicon carbide powder or a combination of a silicon carbide powder and a carbon powder into a desired shape, curing the molded curable silicone composition to yield a cured silicone molded item, and then thermally decomposing the cured silicone molded item under a non-oxidizing atmosphere. The method is capable of simply producing a high-purity silicon carbide molded item having a desired shape and dimensions.Type: ApplicationFiled: October 7, 2010Publication date: August 9, 2012Inventor: Yoshitaka Aoki
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METHOD OF MANUFACTURING SINTERED SILVER ALLOY BODY AND COPPER OXIDE-CONTAINING CLAY-LIKE COMPOSITION
Publication number: 20120098168Abstract: A method of manufacturing a sintered silver alloy body of the present invention includes steps of adding copper oxide to a silver-containing clay-like composition that contains silver-containing metal powder containing silver, a binder, and water to manufacture a clay-like composition for forming a sintered silver alloy body; making an object by making the clay-like composition for forming a sintered silver alloy body into an arbitrary shape; and baking the object in a reduction atmosphere or a non-oxidizing atmosphere after the object is dried.Type: ApplicationFiled: October 24, 2011Publication date: April 26, 2012Applicant: MITSUBISHI MATERIALS CORPORATIONInventors: Takashi Yamaji, Yasuo Ido, Shinji Otani -
Publication number: 20120045633Abstract: An article for magnetic heat exchange comprises a monolithic working component comprising two or more portions. The two or more portions comprise amounts of La, Fe, Si and of one or more elements T and R suitable to produce a La1-aRa(Fe1-x-yTySix)13Hz phase, wherein T is one or more of the elements from the group consisting of Mn, Co, Ni and Cr and R is one or more of the elements from the group consisting of Ce, Nd, Y and Pr. The amount of the one or more elements T and R and the amount of Si is selected for each of the two or more portions to provide the two or more portions with differing Curie temperatures and, preferably, a density, d, within a range of ±5% of an average density, dav, of a total number of portions.Type: ApplicationFiled: February 11, 2011Publication date: February 23, 2012Applicant: Vacuumschmelze GmbH & Co. KGInventors: Matthias KATTER, Volker Zellmann, Alexander Barcza
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Publication number: 20110212825Abstract: The invention relates to a hard-metal comprising at least 13 volume % of a metal carbide selected from the group consisting of TiC, VC, ZrC, NbC, MoC, HfC, TaCl WC or a combination thereof, a binder phase comprising one or more of iron-group metals or alloy thereof and 0.1 to 10 weight % Si and 0.1 to 10 weight % Cr and having a liquidus temperature at 1280 degrees C. or lower and 3 to 39 volume % of diamond or cBN grains coated with a protective coating or a mixture thereof and a process for making the hard-metal.Type: ApplicationFiled: September 15, 2009Publication date: September 1, 2011Inventors: Igor Yuri Konyashin, Bernd Heinrich Ries, Frank Friedrich Lachmann
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Patent number: 7993571Abstract: A ceramic component is provided, including a ceramic body containing silicon carbide, and an oxide layer provided on the ceramic body, the oxide layer being formed by oxidizing the ceramic body in the presence of alumina having a submicron particle size.Type: GrantFiled: June 7, 2010Date of Patent: August 9, 2011Assignee: Saint-Gobain Ceramic & Plastics, Inc.Inventor: Raymond H. Bryden
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Patent number: 7931853Abstract: A process for converting precursor objects into a unitary ceramic object produces, for example, a ceramic, optical scan mirror that is formed from at least two pieces. An optical section has at least one optical surface and at least one attachment surface, and a support section has at least one attachment surface and preferably has a mounting area. The optical and support sections are formed as separate pieces from a precursor material, such as graphite, such that a selected support section can receive any of a plurality of optical sections having different sizes, shapes, or orientations. To form the mirror, the attachment surfaces are placed adjacent each other, and then the sections are converted simultaneously to a ceramic material, such as silicon carbide, to form a monolithic scan mirror.Type: GrantFiled: November 9, 2007Date of Patent: April 26, 2011Assignee: Poco Graphite, Inc.Inventor: Ronald E. Plummer
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Patent number: 7763205Abstract: Method of fabricating RBSN parts in which the processing of compacts of silicon to produce reaction bonded silicon nitride products is accomplished in a continuous style furnace. The furnace of the preferred embodiment is arranged as a contiguous series of furnace sections or zones configured to have a part conveyor traveling slowly from one end to another to sequentially expose the parts to each zone. Each zone may for example be one foot long. The conveyor then travels at a rate of one foot per hour. Parts to be nitrided are settered onto kiln furniture plates while providing a minimum one-quarter inch clearance to all other parts. The parts on the plates are conveyed through the sequential temperature zones in a continuous fashion while under ambient pressure flowing nitrogen gas. The parts travel through the contiguous temperature zones at a constant rate of conveyance allowing the nitriding reaction to progress to completion.Type: GrantFiled: October 22, 2004Date of Patent: July 27, 2010Assignee: Ceradyne, Inc.Inventors: Edwin Todd Voiles, Bijana Mikijelj
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Patent number: 7736582Abstract: A method of consolidating particulate materials into articles having combinations of properties not available by conventional processes by liquid phase sintering. These particulate materials are comprised of core particles individually coated with layers of a metal compound having a relatively higher fracture toughness than the core, such as WC or TaC. These coated particles include an outer layer comprised a metal, such as Co or Ni. The particles with these coatings are pressed to form an article and the article densified at pressures and temperatures where full density is achieved without the degradation of the material forming the core particle.Type: GrantFiled: June 10, 2004Date of Patent: June 15, 2010Assignee: Allomet CorporationInventor: Richard Edmund Toth
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Publication number: 20100093515Abstract: The invention relates to a refractory, ceramically fired, carbon-bonded magnesia brick whose matrix is more than 70% by weight, in particular from 80 to 98% by weight, of MgO grains and also a carbon framework binder matrix resulting from carbonization, and pores, wherein the MgO grains are fixed by means of carbon bonding of the carbon framework and at least 30%, in particular from 50 to 100%, of the MgO grains have at least one sintering bridge resulting from the ceramic firing.Type: ApplicationFiled: February 26, 2008Publication date: April 15, 2010Inventor: Helge Jansen
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Publication number: 20100065991Abstract: The invention relates to a method for production of an object with an at least partly silicon carbide structure from a blank of a carbon-containing material, wherein, in a first step, the object made from the carbon-containing material is produced essentially in the desired end form and/or end size, the object made from the carbon-containing material is then at least partly enveloped in a carbon-rich silicon dioxide granulate and then fired at least once in the envelope in a protective gas atmosphere such that the silicon dioxide granulate gives off gas containing silicon carbide which diffuses into the object and the carbon-containing material is completely or partly converted into silicon carbide.Type: ApplicationFiled: November 22, 2007Publication date: March 18, 2010Inventors: Siegmund Greulich-Weber, Bettina Friedel
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Patent number: 7662320Abstract: A pasty molding material is divided by a process wherein, for the division, the pasty molding material is brought into contact with at least on stream containing at least one fluid medium.Type: GrantFiled: February 4, 2004Date of Patent: February 16, 2010Assignee: BASF AktiengesellschaftInventors: Ulrich Mueller, Jan Mueller
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Patent number: 7648932Abstract: The invention relates to a process for the production of a molded porous ceramic article containing ?-SiC, which process comprises the following steps: the preparation of a molded article containing silicon and carbon and the subsequent pyrolysis and siliconization of the article containing silicon and carbon to form SiC. The invention further relates to a molded porous ceramic article containing SiC which has been produced from a molded article containing silicon and carbon.Type: GrantFiled: July 5, 2006Date of Patent: January 19, 2010Assignee: Mann+Hummel Innenraumfilter GmbH & Co. KGInventors: Lars Weisensel, Thomas Wolff, Heino Sieber, Peter Greil
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Patent number: 7528087Abstract: A porous mullite composition is made by Forming a mixture of one or more precursor compounds having the elements present in mullite (e.g., clay, alumina, silica) and a property enhancing compound. The property enhancing compound is a compound having an element selected from the group consisting of Mg, Ca, Fe, Na, K, Ce, Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, Lu, B, Y, Sc, La and combination thereof. The mixture is shaped and to form a porous green shape which is heated under an atmosphere having a fluorine containing gas to a temperature sufficient to form a mullite composition comprised substantially of acicular mullite grains that are essentially chemically bound.Type: GrantFiled: April 23, 2004Date of Patent: May 5, 2009Assignee: Dow Global Technologies, Inc.Inventors: Chandan Saha, Sharon Allen, Chan Han, Robert T. Nilsson, Arthur R. Prunier, Jr., Aleksander J. Pyzik, Sten A. Wallin, Robin Ziebarth, Timothy J. Gallagher
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Publication number: 20090071293Abstract: The present invention relates to a ceramic filter device for molten metal filtration comprising a major ceramic phase and a minor carbon phase bonded by phosphate bond, a method for producing such filter devices, and the use of such filter devices for the filtration of molten steel.Type: ApplicationFiled: September 4, 2006Publication date: March 19, 2009Inventor: Kassim Juma
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Patent number: 7485246Abstract: A method for fabricating a sintered duplex nuclear fuel pellet includes the steps of: preparing a first powder composed of a material selected from the group consisting of UO2 and UO2—Er2O3, and a second powder composed of UO2—Gd2O3 and a sintering additive; producing a duplex compact consisting of an annular outer portion composed of the first powder and a cylindrical inner portion composed of the second powder; and sintering the duplex compact under a reducing gas atmosphere, wherein the sintering additive contains manganese of 0.001% to 2% by weight based on the total weight of the cylindrical inner portion.Type: GrantFiled: February 2, 2005Date of Patent: February 3, 2009Assignees: Korea Atomic Energy Research Institute, Korea Hydro & Nuclear Power Co., Ltd.Inventors: Young Woo Rhee, Keon Sik Kim, Jong Hun Kim, Ki Won Kang, Jae Ho Yang, Kun Woo Song, Youn Ho Jung
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Patent number: 6933256Abstract: A dielectric ceramic composition comprising at least a main component containing a dielectric oxide of a composition expressed by {(Sr1?xCax)O}m.(Ti1?yZry)O2 and a first subcomponent containing at least one type of compound selected from oxides of V, Nb, W, Ta, and Mo and/or compounds forming these oxides after firing, wherein the symbols m, x, and y showing the molar ratio of the composition in the formula contained in the main component are in relations of 0.94<m<1.08, 0?x?1.00, and 0?y?0.20 and the ratio of the first subcomponent with respect to 100 moles of the main component, which is converted to the metal element in the oxide, is 0.01 mole?first subcomponent<2 moles. According to this dielectric ceramic composition, it is possible to obtain a superior resistance to reduction at the time of firing, obtain a superior capacity-temperature characteristic after firing, and improve the accelerated life of the insulation resistance.Type: GrantFiled: July 30, 2003Date of Patent: August 23, 2005Assignee: TDK CorporationInventors: Takashi Fukui, Yasuo Watanabe, Mikio Takahashi, Akira Sato
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Patent number: 6924038Abstract: A mask suitable for protecting a portion of a substrate surface against diffusion coating of the substrate with a metal, which mask comprises a ceramic material comprising silica and an inert refractory diluent and a metal or metal alloy, wherein the metal or metal alloy is one which is reactive with silicon thereby minimising or preventing siliconisation of the substrate with silicon in the ceramic material under conditions of diffusion coating, and which is reactive with the metal being applied by diffusion coating thereby preventing diffusion coating of the portion of the substrate surface it is desired to protect.Type: GrantFiled: March 28, 2000Date of Patent: August 2, 2005Assignees: Chromalloy United Kingdom Limited, Wade Ceramics LimitedInventors: Bryan Anthony Hardy, David Arthur Goddard, Edward Hugh Shaw
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Patent number: 6849213Abstract: A method for producing a silicon nitride filter including heat-treating in nitrogen a green body containing from 40 to 90% of metal silicon particles having an average particle diameter of from 1 to 200 ?m and from 10 to 60% of a pore-forming agent, where the total amount of the metal silicon particles and the pore-forming agent is at least 90%, forms a porous product made substantially of silicon nitride.Type: GrantFiled: August 13, 2002Date of Patent: February 1, 2005Assignee: Asahi Glass Company, LimitedInventors: Naomichi Miyakawa, Nobuhiro Shinohara, Kanji Arai, Hideo Takahashi
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Patent number: 6793873Abstract: A melt-infiltrated, fiber-reinforced composite ceramic containing high-temperature-resistant fibers, in particular fibers based on Si/C/B/N, which are reaction-bonded to a matrix based on Si and also a process for producing such a composite ceramic are described. The silicon melt which is used for the melt infiltration contains additions of iron, chromium, titanium, molybdenum, nickel or aluminum, with particular preference being given to a silicon melt containing from about 5 to 50% by weight of iron and from about 1 to 10% by weight of chromium. This gives a simplified production process compared with conventional silicon melt infiltration and improved properties of the composite ceramic (FIG. 1).Type: GrantFiled: August 23, 2001Date of Patent: September 21, 2004Assignee: DaimlerChrysler AGInventors: Rainer Gadow, Tilmann Haug, Andreas Kienzle
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Patent number: 6537940Abstract: A ceramic composite containing alkali-metal-&bgr;- or &bgr;″-alumina and an oxygen-ion conductor is fabricated by converting &agr;-alumina to alkali-metal-&bgr;- or &bgr;″-alumina. A ceramic composite with continuous phases of &agr;-alumina and the oxygen-ion conducting ceramic, such as zirconia, is exposed to a vapor containing an alkali-metal oxide, such as an oxide of sodium or potassium. Alkali metal ions diffuse through alkali-metal-&bgr;- or &bgr;″-alumina converted from &agr;-alumina and oxygen ions diffuse through the oxygen-ion conducting ceramic to a reaction front where &agr;-alumina is converted to alkali-metal-&bgr;- or &bgr;″-alumina. A stabilizer for alkali-metal-&bgr;″-alumina is preferably introduced into the &agr;-alumina/oxygen-ion conductor composite or introduced into the vapor used to convert the &agr;-alumina to an alkali-metal-&bgr;″-alumina.Type: GrantFiled: August 10, 2000Date of Patent: March 25, 2003Assignee: Materials and Systems Research, Inc.Inventors: Anil Vasudeo Virkar, Jan-Fong Jue, Kuan-Zong Fung
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Patent number: 6527937Abstract: Methods to at least partially reduce a niobium oxide are described wherein the process includes heat treating the niobium oxide in the presence of a getter material and in an atmosphere which permits the transfer of oxygen atoms from the niobium oxide to the getter material, and for a sufficient time and at a sufficient temperature to form an oxygen reduced niobium oxide. Niobium oxides and/or suboxides are also described as well as capacitors containing anodes made from the niobium oxides and suboxides.Type: GrantFiled: February 19, 2002Date of Patent: March 4, 2003Assignee: Cabot CorporationInventor: James A. Fife
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Patent number: 6461562Abstract: Methods of making metal oxide articles, preferably iron oxide articles, and articles thereby produced. The method comprises the steps of slightly pressing powder to a compact, the powder consisting essentially of a first oxide of the metal; and subjecting the compact to a heat treatment that causes the powder to sinter into a unitary body and results in the transformation of at least a portion of the first oxide to a second oxide by oxidation or deoxidation during the heat treatment. In disclosed embodiments, the heat treatment is conducted either in air at atmospheric pressure or at a subatmospheric pressure. The method optionally includes more heating/cooling steps resulting in additional oxidation/deoxidation cycles. Sintered iron oxide articles of the invention have high mechanical strengths and interconnected pore structures, providing for efficient filtering of liquids and gases.Type: GrantFiled: February 17, 1999Date of Patent: October 8, 2002Assignee: American Scientific Materials Technologies, LPInventors: Konstantin Solntsev, Eugene Shustorovich, Sergei Myasoedov, Vyacheslav Morgunov, Andrei Chernyavsky, Yuri Buslaev, Richard Montano, Alexander Shustorovich
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Patent number: 6451244Abstract: The present invention is intended to provide piezoelectric ceramic materials having far better strain characteristics than that of conventional piezoelectric ceramics, as well as a novel method for producing such piezoelectric ceramics, and the present invention involves solid solution piezoelectric ceramics primarily comprising the complex perovskite compound Pb(Ni⅓Nb⅔)O3, the simple perovskite compound PbTiO3, and PbZrO3, wherein the aforementioned ceramics primarily comprise compositions within a triangle in which the compositional vertices are (X=52, Y=34, Z=14), (X=49, Y=37, Z=14), and (X=49, Y=34, Z=17), where Pb(Ni⅓Nb⅔)O3 is X mol %, PbTiO3 is Y mol %, and PbZrO3 is Z mol % (X+Y+Z=100) among the triangular coordinates in the phase diagram in which the vertices are Pb(Ni⅓Nb⅔) O3, PbTiO3, and PbZrO3, as well as a method for producing such solid solution ceramics.Type: GrantFiled: December 28, 1999Date of Patent: September 17, 2002Assignee: Japan as represented by Secretary of Agency of Industrial Science and TechnologyInventors: Keiji Kusumoto, Tadashi Sekiya
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Publication number: 20020011683Abstract: A plasticizable raw material batch mixture for forming a silicon carbide honeycomb structure comprising the following components: (1) powdered silicon metal; (2) a carbon precursor comprising a water soluble crosslinking thermoset resin having a viscosity of less than about 1000 centipoise (cp), and preferably less than about 500 cp; (3) a powdered silicon-containing filler; and, (4) a water soluble thermoplastic binder. Optionally, the batch mixture can include either, or both, an organic fibrous filler and a pore-forming filler comprising either a graphitic or a thermoplastic pore-forming filler.Type: ApplicationFiled: March 26, 2001Publication date: January 31, 2002Inventors: Kishor P. Gadkaree, Joseph F. Mach, John L. Stempin
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Patent number: 6214523Abstract: A method for serializing ceramic substrates in which a laser is used to remove unfired paste material from an unfired ceramic substrate. The paste material is removed by exposing the unwanted paste material to laser radiation in a programmed sequence of x and y coordinate moves. The laser radiation removes the unwanted paste material, leaving the identifying characters intact. The identifying characters can be used for part identification and traceability.Type: GrantFiled: January 9, 1998Date of Patent: April 10, 2001Assignee: International Business Machines CorporationInventors: Chris T. Kapogiannis, John R. Lankard, Jr., Gerald H. Leino, Thomas J. VanDuynhoven
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Patent number: 6197247Abstract: Molybdenum disilicide/&bgr;′-Si6-zAlzOzN8-z, wherein z=a number from greater than 0 to about 5, composites are made by use of in situ reactions among &agr;-silicon nitride, molybdenum disilicide, and aluminum. Molybdenum disilicide within a molybdenum disilicide/&bgr;′-Si6-zAlzOzN8-z eutectoid matrix is the resulting microstructure when the invention method is employed.Type: GrantFiled: May 26, 1998Date of Patent: March 6, 2001Assignee: The Regents of the University of CaliforniaInventors: Robert P. Rodriguez, John J. Petrovic
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Patent number: 6117807Abstract: A ceramic composite containing alkali-metal-.beta.- or .beta."-alumina and an oxygen-ion conductor is fabricated by converting .alpha.-alumina to alkali-metal-.beta.- or .beta."-alumina. A ceramic composite with continuous phases of .alpha.-alumina and the oxygen-ion conducting ceramic, such as zirconia, is exposed to a vapor containing an alkali-metal oxide, such as an oxide of sodium or potassium. Alkali metal ions diffuse through alkali-metal-.beta.- or .beta."-alumina converted from .alpha.-alumina and oxygen ions diffuse through the oxygen-ion conducting ceramic to a reaction front where .alpha.-alumina is converted to alkali-metal-.beta.- or .beta."-alumina. A stabilizer for alkali-metal-.beta."-alumina is preferably introduced into the .alpha.-alumina/oxygen-ion conductor composite or introduced into the vapor used to convert the .alpha.-alumina to an alkali-metal-.beta."-alumina.Type: GrantFiled: January 2, 1998Date of Patent: September 12, 2000Assignee: Materials and Systems Research, Inc.Inventors: Anil Vasudeo Virkar, Jan-Fong Jue, Kuan-Zong Fung
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Patent number: 6093366Abstract: The present invention provides a ceramic sintered body excellent in oxidation resistance under high temperatures and markedly superior to the conventional ceramic sintered body in the mechanical strength over a wide temperature range of between room temperature and 1,500.degree. C. The ceramic sintered body of the present invention comprises at least one ceramic crystal grain selected from the group consisting essentially of a monosilicate represented by the general formula RE.sub.2 SiO.sub.5, where RE denotes a IIIa group element including yttrium, and a disilicate represented by the general formula RE.sub.2 Si.sub.2 O.sub.7, where RE denotes a IIIa group element including yttrium, and at least one additional element selected from the group consisting of Al, Cr, Hf, Nb, Zr, Ti, V, Ta, Ca and Mg which is segregated in the boundaries of the ceramic crystal grains in an amount of 0.1 to 15% by weight of the sintered body in terms of the oxide thereof.Type: GrantFiled: November 5, 1998Date of Patent: July 25, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Masahiro Kato, Yasuhiro Goto, Takayuki Fukasawa, Toshiaki Mizutani
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Patent number: 6093667Abstract: The present invention provides novel ceramic materials with excellent electrostrictive property, and the present invention relates to electrostrictive ceramics consisting of solid solution ceramics which can be obtained by combining about 30 molar % of primitive perovskite-type compound PbTiO.sub.3 with a composite perovskite compound Pb(Ni.sub.1/3 Nb.sub.2/3)O.sub.3.Type: GrantFiled: February 11, 1999Date of Patent: July 25, 2000Assignee: Agency of Industrial Science and TechnologyInventors: Keiji Kusumoto, Tadashi Sekiya
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Patent number: 5972274Abstract: A conductive wire is electrically heated in a gas atmosphere, wherein a gas reacts with a constituent material of the conductive wire, under gravity-free or micro gravity state. A ceramic is formed on a surface of the wire sa an outer core through a reaction between the wire and the gas and is left by caving an inside wire by melting while maintaining controlled gas convection.Type: GrantFiled: January 22, 1998Date of Patent: October 26, 1999Assignee: National Research Institute for MetalsInventor: Yoshinari Kaieda
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Patent number: 5817274Abstract: Disclosed is a method of manufacturing aluminum nitride, which comprises the steps of preparing a mixed gas consisting essentially of an ammonia gas and at least 0.5% by volume of a hydrocarbon gas, calcining .gamma.-Al.sub.2 O.sub.3 or a precursor thereof at 300.degree. to 1,100.degree. C. so as to prepare the .gamma.-Al.sub.2 O.sub.3 having a moisture content of 1 weight % or less; heating the calcined .gamma.-Al.sub.2 O.sub.3 in the mixed gas at a temperature of 1,200.degree. to 1,700.degree. C., thereby preparing porous aluminum nitride having a specific surface area of 10 m.sup.2 /g or more; and heat-treating the porous aluminum nitride in an atmosphere of an ammonia gas, or a mixed gas of an ammonia gas and an inert gas, at 1600.degree. to 2000.degree. C., so as to make contents of both carbon and oxygen contained in the aluminum nitride 1 weight % or less.Type: GrantFiled: September 4, 1997Date of Patent: October 6, 1998Assignees: Toshiba Ceramics Co., Ltd., Toshiba Monofrax Co., Ltd.Inventors: Hiroaki Kotaka, Hidenori Yamaoka, Shuitsu Matsuo, Masahiro Ando, Mikiya Fujii, Hiroyuki Terada, Yasuo Misu
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Patent number: 5762864Abstract: A lightweight artificial aggregate manufacturing method includes the steps of: mixing aggregate sludge, whose moisture content exceeds 30%, with stone fragments, generated when pulverizing stone, to decrease the moisture content, mixing this mixture and sewage disposal plant sludge, which are dried and micro-pulverized, in a weight ratio of 50 to 50, and making the mixed sludge spheroids with a rotary plate molding device; applying paper sludge, which is dried and micro-pulverized, to the surface of the spheroids in order to prevent condensation of the spheroid during burning and to light the weight of aggregate; burning the spheroid with reducing flame of a temperature between 1000.degree. C. and 1200.degree. C. in a burning furnace, which uses gas or oil as fuel; and cooling the burned spheroid.Type: GrantFiled: June 12, 1997Date of Patent: June 9, 1998Assignee: Gom Remicon Co., Ltd.Inventor: Yong Deuk Park