Including Reaction Of Precursor To Form New Inorganic Compound Or Composition Patents (Class 264/658)
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Patent number: 6358441Abstract: A transparent scintillator material for rapid conversion of exciting radiation, such as x-rays, to scintillating radiation. The scintillator material has a cubic garnet host, and has praseodymium as an activator. The scintillator material may be a polycrystalline ceramic material. The polycrystalline ceramic is formed by sintering a powder formed by precipitation. The scintillator material may be integrated into computed tomography (CT) equipment or other x-ray imaging equipment. The scintillator material may also be integrated into a fast response x-ray detector system.Type: GrantFiled: April 6, 2001Date of Patent: March 19, 2002Assignee: General Electric CompanyInventors: Steven Jude Duclos, Alok Mani Srivastava
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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
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Patent number: 6251335Abstract: The process incorporating the invention enables fabrication of dense, highly textured (fraction of oriented grains >20 vol. %) alumina. The method uses a mixture of aluminum metal powder, alumina powder, tabular alumina grains and a liquid phase former. A dry powder mixtures of these components is compacted by dry forming techniques such as roll compaction, uniaxial pressing, forging and/or double action pressing. The formed part is then heated at 0.5-10° C./min. to a temperature between 450 and 500° C. and is held for 2-15 h, and is then heated at 1-10° C/min. to 900-1070° C. and is held for 2-10 hours to convert the aluminum particles into alumina. The part is then heated to a higher temperature (>1400° C.) to form a liquid phase which assists densification and promotes the growth of the tabular alumina grains. The aspect ratio range of the textured alumina grains is from 2-14.Type: GrantFiled: April 30, 1999Date of Patent: June 26, 2001Assignee: The Penn State Research FoundationInventors: Gary L. Messing, Ender Suvaci
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Patent number: 6228293Abstract: A process for producing a body having a porous matrix of at least one recrystallized ceramic material, or for producing a similar fiber-reinforced body, includes shaping a raw material batch which contains a raw material powder and then sintering. A raw material powder is used which has grain size distribution of a fine grain fraction of an average grain size of at most approximately 2 &mgr;m and a coarse grain fraction of an average grain size of approximately 1.5 &mgr;m to approximately 30 &mgr;m, and the sintering process is carried out at a temperature of at most approximately 1,800° C. Because of the selected grain sizes and grain size distributions, the sintering process can be carried out at lower temperatures. In particular, reinforcing fibers can be worked in which can withstand higher sintering temperatures. By defining the grain size of the powder, a porosity can also be set which permits a good impregnating with organic and/or inorganic substances.Type: GrantFiled: August 24, 1998Date of Patent: May 8, 2001Assignee: DaimlerChrysler AGInventors: Jochen Kriegsmann, Rolf Meistring, Nicole Neumann, Reinhard Nixdorf
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Patent number: 6200526Abstract: A process for preparing complex-shaped, ceramic-metal composite articles, comprising: (a) contacting a non-wettable powder that is non-wetting to a metal to be used for infiltration with a shaped ceramic body to form a layer of the non-wettable powder on one or more surfaces of the shaped ceramic body, wherein the shaped ceramic body has a region where there is no layer of the non-wettable powder, and (b) infiltration the shaped ceramic body with the metal through the region or regions where there is no layer of the non-wettable powder, such that a complex-shaped ceramic-metal composite comprising one or more metal phases and one or more ceramic phases is formed, wherein the article has substantially the net shape of the shaped ceramic body and undesirable regions of excess metal on the surface and undesirable phases within the complex-shaped ceramic-metal composite article near the surface are located only in the region or regions where there is no layer of the non-wettable powder.Type: GrantFiled: May 11, 1999Date of Patent: March 13, 2001Assignee: The Dow Chemical CompanyInventors: Richard T. Fox, Aleksander J. Pyzik, Chan Han, Robert T. Nilsson
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Patent number: 6197248Abstract: A process for preparing a powder of aluminum titanate, including the steps of subjecting to pressure molding a mixture of 100 parts by weight of a mixture of Al2O3 and TiO2 at a molar ratio of the former: the latter of 1:0.95-1.05, 2 to 5 parts by weight of SiO2, 2 to 5 parts by weight of iron oxide calculated as Fe2O3 and 1 to 3 parts by weight of a powder of an organic substance; sintering the molded product at a temperature of 1600 to 1700° C. in a closed container; and pulverizing the molded product. A further process for preparing a sintered body of aluminum titanate includes the steps of molding the powder of aluminum titanate obtained by the above-mentioned process and sintering the molded product at 1450 to 1550° C.Type: GrantFiled: August 6, 1999Date of Patent: March 6, 2001Inventors: Tsutomu Fukuda, Masahiro Fukuda
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Patent number: 6187253Abstract: An indium oxide/tin oxide powder with 5-15 wt. % tin oxide is subjected to an annealing treatment at T≧1, 000° C. and is then partially reduced and subjected to hot isostatic pressing to produce a sputtering target with a density of at least 95% of the theoretical density and a thermal conductivity of at least 14 Wm−1K−1.Type: GrantFiled: November 3, 1997Date of Patent: February 13, 2001Assignee: Leybold Material GmbHInventors: Martin Schlott, Wolfgang Dauth, Martin Kutzner, Bruce Gehman, Shawn Vahlstrom
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Patent number: 6156259Abstract: In a method of manufacturing piezoelectric ceramics by molding pre-fired or calcined powders of ingredients of a piezoelectric ceramic material and sintering the powder mold at a high pressure, the powder mold is pre-sintered at an atmospheric pressure before sintering at high pressure (HIP). Preferably, after the sintering HIP step, a thermal treatment is performed at a temperature of from 500 to 1000.degree. C. under an oxidizing atmosphere. For a Pb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 --PbTiO.sub.3 based piezoelectric ceramic, the composition is preferably set to (Pb.sub.1-x Ba.sub.x)[(Zn.sub.1/3 Nb.sub.2/3).sub.1-y Ti.sub.y ]O.sub.3, where 0.001<x<0.055 and 0.05<y<0.20.Type: GrantFiled: October 6, 1995Date of Patent: December 5, 2000Assignee: Fujitsu LimitedInventors: Motoyuki Nishizawa, Mineharu Tsukada, Kaoru Hashimoto, Nobuo Kamehara
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Patent number: 6126888Abstract: A method for making very strong gas mantles and other ceramic structures, and the resulting products, are provided. According to the method, an organic or composite structure is first pyrolyzed in the absence of oxygen to remove hydrogen, oxygen and nitrogen, leaving a porous carbon or composite structure, which is then impregnated with a metal compound-containing solution or slurry which is later fired in the presence of an oxidizing atmosphere to produce a refractory metal oxide which has about the same shape as the precursor carbon or composite structure. Due to minimal shrinkage of the mostly carbon or composite precursor, the resulting mantles and other ceramic structures have few defects in the fibers and great strength.Type: GrantFiled: January 8, 1999Date of Patent: October 3, 2000Assignee: Quantum Group Inc.Inventor: Mark K. Goldstein
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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: 6063160Abstract: The invention relates to a method and apparatus for sintering finely divided material, containing manganese compounds with a particle size less than 6 mm and a high degree of oxidation, by means of some carbon-bearing material in a conveyor-type sintering apparatus (9) in an essentially continuous operation. According to the invention, through the material (8) to be sintered in the sintering apparatus (9), there is conducted hot gas (15, 18), which causes combustion reactions between the manganese compounds contained in the material and having a high degree of oxidation and the carbon contained in the burning material. Thus the sintering (18) is carried out essentially by means of the combustion heat released from the material (8). Moreover, the sintered material (8) is subjected to cooling (17) prior to removing the material from the sintering apparatus (9).Type: GrantFiled: March 25, 1998Date of Patent: May 16, 2000Assignee: Outokumpu OyjInventors: Helge Krogerus, Jorma Daavittila, Paivi Oikarinen
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Patent number: 5925405Abstract: In a method of manufacturing ceramic, metallic shaped bodies or layers a castable moldable material mass consisting of sugar and/or urea-containing compounds as well as metal components is produced and from that material mass a shaped body is formed or the material mass is applied to a material structure and the shaped body or material structure is then heated and sintered. The sugar material mass includes for example sugar syrup, sugar or beets, cane sugar, fruits, honey, alcohol-sugar solutions and beer.Type: GrantFiled: August 19, 1997Date of Patent: July 20, 1999Inventor: Imran Ali-Khan
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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
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Patent number: 5795537Abstract: The present invention provides a method of producing composite oxide ceramics which is capable of efficiently producing single-phase multi-component metal oxide ceramics having less impurity phase and excellent dielectric characteristics, by a simple process comprising sintering at a low temperature. The method has the steps of mixing a metallic hydroxide or hydrous gel with a plurality of metallic oxide powders to prepare a raw material mixture powder, activating the raw material mixture powder by mechanochemical treatment for grinding the raw material mixture powder with a degree of impact, which provides a centrifugal effect of 15 or more, to form a precursor, and synthesizing composite oxide ceramics by heat treatment of the activated raw material mixture powder (precursor).Type: GrantFiled: August 7, 1996Date of Patent: August 18, 1998Assignee: Nara Machinery Co., Ltd.Inventors: Mamoru Senna, Sang-Hee Cho, Kenji Hamada
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Patent number: 5762862Abstract: The invention is directed to a method of firing ceramics and a furnace for manufacturing ceramics. Ceramic forms are first fired in a cylindrical heat resistant container in a furnace core tube by using a lateral tubular furnace to increase their mechanical strength. Then, the container is rotated while the ceramic forms are fired further in a predetermined temperature region, which includes a maximum temperature. In this manner the ceramic forms are heated in a uniform state, both thermally and atmospherically, while receiving moderate impact by rotation, and defective appearance and fluctuations in the characteristics of the ceramics are suppressed. In particular, the container is rotated within a temperature region which is higher than the temperature used to start increasing the mechanical strength of the ceramic forms. Further, the ceramic forms can be packed into the container at a higher rate during the rotation portion of the process than during the first firing.Type: GrantFiled: November 7, 1996Date of Patent: June 9, 1998Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Hideyuki Okinaka, Yasuo Wakahata, Toru Fukada
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Patent number: 5756042Abstract: A process is proposed for producing non-oxidic ceramic having a thermal conductivity in a predetermined range. A shaped body of non-oxidic ceramic material is heated to remove organic constituents, and is subsequently thermally treated in an oxygen-containing atmosphere to incorporate oxygen atoms into the crystal lattice of the non-oxidic ceramic, with the temperature and/or the hold time at this temperature being selected as a function of the predetermined thermal conductivity range, and the shaped body is finally sintered in a non-oxidizing atmosphere.Type: GrantFiled: February 21, 1995Date of Patent: May 26, 1998Assignee: Hoechst AktiengesellschaftInventors: Rainer Buckpesch, Hans-Michael Guther, Christine Kostler, Andreas Roosen, Katharina Seitz
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Patent number: 5733498Abstract: A silicon nitride reaction-sintered body having a high mechanical strength without surface working can be produced by (1) forming a silicon powder mixture of at least two types of silicon powders having substantially independent particle size distribution ranges into a green body, the silicon powder mixture having an average particle size ranging from 5 .mu.m to 300 .mu.m; (2) heating the green body in a nitrogen-containing atmosphere for nitrogenation; and (3) sintering the nitrogenated green body at a temperature of 1900.degree. C. or higher.Type: GrantFiled: May 20, 1996Date of Patent: March 31, 1998Assignee: Honda Giken Kogyo Kabushiki KaishaInventors: Yasunobu Kawakami, Kazumi Miyake, Hitoshi Toyoda, Naoki Ota, Kagehisa Hamazaki
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Patent number: 5667742Abstract: The present invention relates to novel methods for shaping a filler material into a porous preform and subsequently filling at least a portion of the porous preform with a second material to form a composite body. Specific aspects of the invention include novel combinations of materials to form the preform in combination with novel processing techniques for shaping the combinations of materials into a porous preform.Type: GrantFiled: June 15, 1994Date of Patent: September 16, 1997Assignee: Lanxide Technology Company, LPInventors: Ratnesh Kumar Dwivedi, Thomas James Henderson, David Francis Friel