With Alkaline Earth Metal Compound Patents (Class 501/97.3)
  • Patent number: 11355416
    Abstract: A structure includes: a ? silicon nitride crystal phase; and a Y2MgSi2O5N crystal phase. The structure gives a X-ray diffraction pattern by a ?-2? method, the pattern having a ratio of a peak intensity of a (22-1) plane of the Y2MgSi2O5N crystal phase to a peak intensity of a (200) plane of the ? silicon nitride crystal phase, the peak intensity of the (200) plane being determined at a position of 2?=27.0±1°, the peak intensity of the (22-1) plane being determined at a position of 2?=30.3±1°, and the ratio being 0.001 or more and 0.01 or less.
    Type: Grant
    Filed: August 31, 2020
    Date of Patent: June 7, 2022
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yumi Fukuda, Koichi Harada, Yasushi Hattori, Maki Yonetsu, Kenji Essaki, Keiko Albessard, Yasuhiro Goto
  • Patent number: 9630846
    Abstract: A silicon nitride substrate including silicon nitride crystal grains and a grain boundary phase and having a thermal conductivity of 50 W/m·K or more, wherein, in a sectional structure of the silicon nitride substrate, a ratio (T2/T1) of a total length T2 of the grain boundary phase in a thickness direction with respect to a thickness T1 of the silicon nitride substrate is 0.01 to 0.30, and a variation from a dielectric strength mean value when measured by a four-terminal method in which electrodes are brought into contact with a front and a rear surfaces of the substrate is 20% or less. The dielectric strength mean value of the silicon nitride substrate can be 15 kV/mm or more. According to above structure, there can be obtained a silicon nitride substrate and a silicon nitride circuit board using the substrate in which variation in the dielectric strength is decreased.
    Type: Grant
    Filed: October 21, 2014
    Date of Patent: April 25, 2017
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.
    Inventors: Noritaka Nakayama, Katsuyuki Aoki, Takashi Sano
  • Publication number: 20150099619
    Abstract: A ceramic material for radome is illustrated comprising: —about 80-95% (% wt) of Si3N4; about 5-15% (wt %) of magnesium aluminosilicates including 2.5-12.5% (wt %) of Si02, 0.5-3% (wt %) of MgO and 2-6% (wt %) of Al203; and having a density not lower than 2.5 g/cm3 and a dielectric constant not exceeding 6.5. A process for producing a radome is also illustrated.
    Type: Application
    Filed: February 22, 2012
    Publication date: April 9, 2015
    Applicant: MBDA ITALIA S.p.A.
    Inventors: Daniela Di Martino, Seiti Diletta, Laura Esposito
  • Patent number: 8772190
    Abstract: The invention concerns a sintered ceramic component of silicon nitride or sialon suitable as rolling element in a bearing and a manufacturing method for making such ceramic components. The ceramic component has high density and a homogeneous and fine microstructure, giving the component excellent mechanical properties. Manufacturing of the sintered ceramic component by SPS is cost-effective and rapid.
    Type: Grant
    Filed: August 29, 2008
    Date of Patent: July 8, 2014
    Assignee: AB SKF
    Inventors: Zhijian Shen, Saeid Esmaeilzadeh, Katarina Flodstrom, Charlotte Vieillard
  • Patent number: 8741797
    Abstract: A composite article having a body including a first phase that includes a nitride material, a second phase that includes a carbide material, and a third phase having one of an amorphous phase material with a nitrogen content of at least about 1.6 wt % or an amorphous phase material comprising carbon.
    Type: Grant
    Filed: September 27, 2012
    Date of Patent: June 3, 2014
    Assignee: Saint-Gobain Ceramics & Plastics, Inc.
    Inventors: Christopher J. Reilly, Vimal K. Pujari, Edmund A. Cortellini, David M. McElwee
  • Patent number: 8673795
    Abstract: A silicon nitride material is disclosed which has properties necessary for efficient operation of a corona discharge igniter system in an internal combustion gas engine allowing an increase in fuel efficiency of over 10%. The material is disclosed in a range of compositions, all of which exhibit high dielectric strengths, high mechanical strength, thermal shock resistance and fracture toughness, low dielectric constant and loss tangent and electrical resistivity, all of which significantly increase the efficiency of the igniter system over current state of the art alumina insulators. Moreover, the materials retain their dielectric strength and structural integrity at elevated temperatures, up to 800° C.-1000° C. One embodiment comprises a sintered silicon nitride process comprising powder batching, binder removal and sintering. In the preferred embodiment the method of manufacture for silicon nitride is an SRBSN process comprising powder batching, powder pressing, binder removal, nitriding and sintering.
    Type: Grant
    Filed: December 16, 2011
    Date of Patent: March 18, 2014
    Assignee: Ceradyne, Inc.
    Inventor: Biljana Mikijelj
  • Patent number: 8652981
    Abstract: Silicon nitride materials with high strength, fracture toughness values, and Weibull moduli simultaneously, due to unique large grain reinforcing microstructures and well engineered grain boundary compositions. The invention demonstrates that, surprisingly and contrary to prior art, a silicon nitride material can be made which simultaneously has high strength above about 850-900 MPa, a Weibull above about 15 and high fracture toughness (above about 8 and 9 MPa·m1/2), and has reinforcing grains longer than 5 ?m, typically longer than 10 ?m in the microstructure without compromising its properties and reliability. The product of this invention can be processed using a variety of densification methods, including gas-pressure sintering, hot pressing, hot isostatic pressing, but is not limited to these, and does not require multiple heat treatments for all of these features to be achieved.
    Type: Grant
    Filed: January 21, 2010
    Date of Patent: February 18, 2014
    Assignee: Ceradyne, Inc.
    Inventor: Biljana Mikijelj
  • Patent number: 8586493
    Abstract: A silicon nitride sintered body, wherein in a silicon nitride substrate consisting of crystal grains of ?-type silicon nitride and a grain boundary phase containing at least one type of rare earth element (RE), magnesium (Mg) and silicon (Si), the grain boundary phase consists of an amorphous phase and a MgSiN2 crystal phase. The X-ray diffraction peak intensity of any crystal plane of a crystal phase containing the rare earth element (RE) is less than 0.0005 times the sum of the diffraction peak intensities of (110), (200), (101), (210), (201), (310), (320) and (002) of the crystal grains of the ?-type silicon nitride; and the X-ray diffraction peak intensity of (121) of the MgSiN2 crystal phase is 0.0005 to 0.003 times the sum of the X-ray diffraction peak intensities of (110), (200), (101), (210), (201), (310), (320) and (002) of the crystal grains of the ?-type silicon nitride.
    Type: Grant
    Filed: July 3, 2009
    Date of Patent: November 19, 2013
    Assignee: Hitachi Metals, Ltd.
    Inventors: Youichirou Kaga, Junichi Watanabe
  • Patent number: 8496718
    Abstract: A silicon nitride cutting tool comprising a sintered product is disclosed. The sintered product comprises silicon nitride, at least one rare earth element compound, and a magnesium compound. The silicon nitride cutting tool further comprises a surface region and an inside region comprising the sintered product with varying content ratios of component compounds to provide enhanced wear and fracture resistance.
    Type: Grant
    Filed: March 25, 2009
    Date of Patent: July 30, 2013
    Assignee: Kyocera Corporation
    Inventors: Takashi Watanabe, Tatsuyuki Nakaoka, Takero Fukudome, Shuichi Tateno, Hiroshi Yoshimitsu
  • Patent number: 8492300
    Abstract: An insert includes a silicon nitride sintered body including ?-Si3N4 as a main component, Mg, and a rare-earth element Re (Y, La, Ce, Er, Dy, Yb). A content of Mg in terms of MgO is 1.0-7.0 mol %, a content of Re in terms of an oxide thereof is 0.4-1.0 mol %, and a total content of Mg and Re is from 1.7 to less than 7.5 mol %. The insert has a graded composition in which oxygen content increases from a surface of the sintered body toward an inside thereof such that 0.8-1.5 mass % of oxygen is contained in a region of less than 0.5 mm inside from the surface, 1.1-2.3 mass % of oxygen is contained in a region of 0.5 mm or more inside from the surface, and a difference in oxygen content between the regions is 0.1-1.0 mass %.
    Type: Grant
    Filed: March 14, 2008
    Date of Patent: July 23, 2013
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Ryoji Toyoda, Yusuke Suzuki, Yuki Hatano
  • Patent number: 8377837
    Abstract: A wear resistant member formed of silicon nitride sintered body having a volume of 4000 mm3 or more, the silicon nitride sintered body containing 1 to 5 mass % of a rare earth component in terms of rare earth element, 1 to 6 mass % of an Al component in terms of Al element, 10 to 3500 ppm of an Fe component in terms of Fe element, and 10 to 1000 ppm of a Ca component in terms of Ca element, wherein a ?-phase ratio of silicon nitride crystal grains is 95% or more, a maximum longer diameter of the silicon nitride crystal grains is 40 ?m or less, and each of dispersions in Vickers hardness and fracture toughness of an inner portion of the wear resistant member is within a range of ±10%. According to this structure, the wear resistant member can be manufactured with a low cost, and there can be provided a wear resistant member comprising a silicon nitride sintered body excellent in reliability and the dispersion in characteristics is effectively suppressed.
    Type: Grant
    Filed: April 9, 2009
    Date of Patent: February 19, 2013
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.
    Inventor: Minoru Takao
  • Publication number: 20120190530
    Abstract: Silicon nitride materials with high strength, fracture toughness values, and Weibull moduli simultaneously, due to unique large grain reinforcing microstructures and well engineered grain boundary compositions. The invention demonstrates that, surprisingly and contrary to prior art, a silicon nitride material can be made which simultaneously has high strength above about 850-900 MPa, a Weibull above about 15 and high fracture toughness (above about 8 and 9 MPa·m1/2), and has reinforcing grains longer than 5 ?m, typically longer than 10 ?m in the microstructure without compromising its properties and reliability. The product of this invention can be processed using a variety of densification methods, including gas-pressure sintering, hot pressing, hot isostatic pressing, but is not limited to these, and does not require multiple heat treatments for all of these features to be achieved.
    Type: Application
    Filed: January 21, 2010
    Publication date: July 26, 2012
    Inventor: Biljana Mikijelj
  • Publication number: 20110176277
    Abstract: Provided are a silicon nitride substrate made of a silicon nitride sintered body that is high in strength and thermal conductivity, a method of producing the silicon nitride substrate, and a silicon nitride circuit substrate and a semiconductor module that use the silicon nitride substrate. According to the silicon nitride sintered body, in a silicon nitride substrate consisting of crystal grains 11 of ?-type silicon nitride and a grain boundary phase containing at least one type of rare earth element (RE), magnesium (Mg) and silicon (Si), the grain boundary phase consists of an amorphous phase 12 and a MgSiN2 crystal phase 13; the X-ray diffraction peak intensity of any crystal plane of a crystal phase containing the rare earth element (RE) is less than 0.0005 times the sum of the diffraction peak intensities of (110), (200), (101), (210), (201), (310), (320) and (002) of the crystal grains of the ?-type silicon nitride; and the X-ray diffraction peak intensity of (121) of the MgSiN2 crystal phase 13 is 0.
    Type: Application
    Filed: July 3, 2009
    Publication date: July 21, 2011
    Applicant: HITACHI METALS, LTD.
    Inventors: Youichirou Kaga, Junichi Watanabe
  • Patent number: 7968484
    Abstract: A high-strength, fracture-resistant silicon nitride ceramic material that includes about 5 to about 75 wt-% of elongated reinforcing grains of beta-silicon nitride, about 20 to about 95 wt-% of fine grains of beta-silicon nitride, wherein the fine grains have a major axis of less than about 1 micron; and about 1 to about 15 wt-% of an amorphous intergranular phase comprising Si, N, O, a rare earth element and a secondary densification element. The elongated reinforcing grains have an aspect ratio of 2:1 or greater and a major axis measuring about 1 micron or greater. The elongated reinforcing grains are essentially isotropically oriented within the ceramic microstructure. The silicon nitride ceramic exhibits a room temperature flexure strength of 1,000 MPa or greater and a fracture toughness of 9 MPa-m(1/2) or greater. The silicon nitride ceramic exhibits a peak strength of 800 MPa or greater at 1200 degrees C.
    Type: Grant
    Filed: September 7, 2007
    Date of Patent: June 28, 2011
    Assignee: UT-Battelle, LLC
    Inventors: Paul F. Becher, Hua-Tay Lin
  • Patent number: 7964296
    Abstract: High-volume, fully dense, multi-component monoliths with microstructurally indistinguishable joints that can be used as refractory, corrosion and wear resistant components in the non-ferrous metal industry. The Si3N4 monoliths according to the invention comprise at least 90% by weight ?-type Si3N4 and up to 10% by weight of a predominantly amorphous binder phase, said binder phase being formed from compositions of the rare earth metal —Al—Si—O—N, rare earth metal —Mg—Si—O—N or Mg—Si—O—N systems. Preferably the rare earth metal is yttrium (Y). The monoliths have a volume of greater than 250 cm3. A method of making the multi-component monoliths is achieved by simultaneously joining and uniaxially hot pressing an assembly of reaction bonded silicon nitride bodies (RBSN bodies). RBSN bodies are placed in contact with each other in the substantial absence of any interlayer or ceramic paste in between.
    Type: Grant
    Filed: July 27, 2007
    Date of Patent: June 21, 2011
    Assignee: Ceradyne, Inc.
    Inventor: Biljana Mikijelj
  • Patent number: 7749932
    Abstract: A sintered product of silicon nitride includes a crystal phase mainly having silicon nitride crystal grains and an amorphous grain-boundary phase located on the grain boundaries of the silicon nitride crystal grains. The grain-boundary phase contains lanthanum, aluminum, magnesium, silicon, and oxygen. The sintered product described above contains 0.1% by mass or more of lanthanum on an oxide basis, 0.05 to 0.6% by mass of aluminum on an oxide basis, 0.3% by mass or more of magnesium on an oxide basis, and 2.5% by mass or less of oxygen. The total amount of lanthanum on an oxide basis, aluminum on an oxide basis, and magnesium on an oxide basis is 3.5% by mass or less.
    Type: Grant
    Filed: February 21, 2008
    Date of Patent: July 6, 2010
    Assignee: Kyocera Corporation
    Inventors: Takero Fukudome, Shuichi Tateno, Hiroshi Yoshimitsu, Takashi Watanabe, Tatsuyuki Nakaoka
  • Publication number: 20100093513
    Abstract: A refractory composition having excellent erosion resistance and infiltration resistance to a molten metal and a formed article and a sintered article produced from the refractory composition are provided. The refractory composition comprises for 100 parts by mass of at least one compound selected from the group consisting of silicon nitride, boron nitride, and silicon carbide, 5 to 40 parts by mass of at least one compound selected from the group consisting of calcium fluoride, magnesium fluoride, calcium oxide or its precursor, magnesium oxide or its precursor, barium oxide or its precursor, and barium sulfate. The content of the silicon nitride, boron nitride, and silicon carbide in the composition is 20 mass % or more.
    Type: Application
    Filed: January 13, 2009
    Publication date: April 15, 2010
    Inventors: Shigeru Nakama, Norihiro Kihara, Munehiko Fukase
  • Publication number: 20100040424
    Abstract: An insert includes a silicon nitride sintered body including ?-Si3N4 as a main component, Mg, and a rare-earth element Re (Y, La, Ce, Er, Dy, Yb). A content of Mg in terms of MgO is 1.0-7.0 mol %, a content of Re in terms of an oxide thereof is 0.4-1.0 mol %, and a total content of Mg and Re is from 1.7 to less than 7.5 mol %. The insert has a graded composition in which oxygen content increases from a surface of the sintered body toward an inside thereof such that 0.8-1.5 mass % of oxygen is contained in a region of less than 0.5 mm inside from the surface, 1.1-2.3 mass % of oxygen is contained in a region of 0.5 mm or more inside from the surface, and a difference in oxygen content between the regions is 0.1-1.0 mass %.
    Type: Application
    Filed: March 14, 2008
    Publication date: February 18, 2010
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Ryoji Toyoda, Yusuke Suzuki, Yuki Hatano
  • Patent number: 7638200
    Abstract: A composition and method for fabricating high-density Ta—Al—O, Ta—Si—N, and W—Si—N sputtering targets, having particular usefulness for the sputtering of heater layers for ink jet printers. Compositions in accordance with the invention comprise a metal component, Si3N4, and a sintering aid so that the targets will successfully sputter without cracking, etc. The components are combined in powder form and pressure consolidated under heated conditions for a time sufficient to form a consolidated blend having an actual density of greater that about 95% of the theoretical density. The consolidated blend may then be machined so as to provide the final desired target shape.
    Type: Grant
    Filed: August 27, 2003
    Date of Patent: December 29, 2009
    Assignees: Tosoh SMD, Inc., Hewlett-Packard Company
    Inventors: David B. Smathers, Frank S. Valent, Michael J. Regan
  • Patent number: 7612006
    Abstract: To provide a sintered silicon nitride with conductivity and densification, an oxide of titanium group elements, such as titanium oxide, hafnium oxide, zirconium oxide and the like, aluminum oxide and/or aluminum nitride is added as needed to silicon nitride-oxidant of rare-earth elements-aluminum oxide system or silicon nitride-oxide of rare-earth elements-magnesia system, and then specified quantity of carbon nonotube (CNT) is added to the above mixture. CNT generates silicon carbide after the reaction with contiguous or proximal silicon nitride and the like depending on the sintering duration at high temperature. Since silicon carbide is generated along with nanotubes, the silicon carbide functions as conductor with excellent heat resistance, corrosion resistance and the like.
    Type: Grant
    Filed: September 27, 2005
    Date of Patent: November 3, 2009
    Assignee: Yokohama TLO Company, Ltd.
    Inventors: Katsutoshi Komeya, Junichi Tatami, Takeshi Meguro, Tomofumi Katashima, Toru Wakihara
  • Patent number: 7521388
    Abstract: A silicon nitride abrasion resistant member is formed of silicon nitride sintered body containing 2% to 4% by mass of a rare earth element in terms of oxide thereof as a sintering aid, 2% to 6% by mass of an Al component in terms of oxide thereof, and 2% to 7% by mass of silicon carbide. The silicon nitride sintered body has a porosity of 1% or less, a three-point bending strength of 800 to 1000 MPa, and a fracture toughness of 5.7 to 6.5 MPa·m1/2. According to this structure, even when an inexpensive silicon nitride powder manufactured by metal nitriding method is used, there can be provided a silicon nitride abrasion resistant member having a mechanical strength, high abrasion resistance, and a rolling life, equal to or higher than those of conventional silicon nitride sintered bodies, and excellent workability, and a method for manufacturing the member can be provided.
    Type: Grant
    Filed: September 27, 2004
    Date of Patent: April 21, 2009
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.
    Inventors: Michiyasu Komatsu, Minoru Takao
  • Patent number: 7498284
    Abstract: A nitride glass with the general formula ?x?y?z is provided wherein ? is a glass modifier comprising at least one electropositive element. ? comprises Si, B, Ge, a and/or Al. ? is N or N together with O, whereby the atomic ratio of O:N is in the interval from 65:35 to 0:100.
    Type: Grant
    Filed: January 14, 2004
    Date of Patent: March 3, 2009
    Assignee: Diamorph AB
    Inventor: Saeid Esmaeilzadeh
  • Publication number: 20090029843
    Abstract: High-volume, fully dense, multi-component monoliths with microstructurally indistinguishable joints that can be used as refractory, corrosion and wear resistant components in the non-ferrous metal industry. The Si3N4 monoliths according to the invention comprise at least 90% by weight ?-type Si3N4 and up to 10% by weight of a predominantly amorphous binder phase, said binder phase being formed from compositions of the rare earth metal —Al—Si—O—N, rare earth metal —Mg—Si—O—N or Mg—Si—O—N systems. Preferably the rare earth metal is yttrium (Y). The monoliths have a volume of greater than 250 cm3. A method of making the multi-component monoliths is achieved by simultaneously joining and uniaxially hot pressing an assembly of reaction bonded silicon nitride bodies (RBSN bodies). RBSN bodies are placed in contact with each other in the substantial absence of any interlayer or ceramic paste in between.
    Type: Application
    Filed: July 27, 2007
    Publication date: January 29, 2009
    Inventor: Biljana Mikijelj
  • Publication number: 20080220243
    Abstract: A sintered product of silicon nitride includes a crystal phase mainly having silicon nitride crystal grains and an amorphous grain-boundary phase located on the grain boundaries of the silicon nitride crystal grains. The grain-boundary phase contains lanthanum, aluminum, magnesium, silicon, and oxygen. The sintered product described above contains 0.1% by mass or more of lanthanum on an oxide basis, 0.05 to 0.6% by mass of aluminum on an oxide basis, 0.3% by mass or more of magnesium on an oxide basis, and 2.5% by mass or less of oxygen. The total amount of lanthanum on an oxide basis, aluminum on an oxide basis, and magnesium on an oxide basis is 3.5% by mass or less.
    Type: Application
    Filed: February 21, 2008
    Publication date: September 11, 2008
    Applicant: KYOCERA CORPORATION
    Inventors: Takero Fukudome, Shuichi Tateno, Hiroshi Yoshimitsu, Takashi Watanabe, Tatsuyuki Nakaoka
  • Publication number: 20080114468
    Abstract: A process for making a sintered ceramic medical device, comprising providing an unsintered ceramic composition, forming the unsintered ceramic composition into a green body that comprises unsintered ceramic, irradiating the green body with microwave radiation, and cooling the sintered body. The microwave radiation has a frequency capable of heating the unsintered ceramic to a temperature sufficient to sinter the green body, thereby preparing a sintered ceramic medical device. A medical device comprising volumetrically sintered ceramic, and a volumetrically sintered ceramic are also disclosed.
    Type: Application
    Filed: November 10, 2006
    Publication date: May 15, 2008
    Applicant: Biomet Manufacturing Corp.
    Inventor: Mukesh Kumar
  • Patent number: 7294596
    Abstract: A sintered ceramic material comprises a crystalline phase and an intergranular phase comprising a glass phase. The material is manufactured from a starting powder being mixed with an additive comprising one or more metal from a group of Li, Na, Mg, Ca, Sr, Ba, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Th, Pa or U. The additive is in non oxide form, or in a form which transforms to a metal or nitride during a synthesis in nitrogen atmosphere and the resulting glass phase having a high nitrogen content with a N:O ratio higher than 35:65 and a glass transition temperature above 950° C.
    Type: Grant
    Filed: March 14, 2005
    Date of Patent: November 13, 2007
    Assignee: Diamorph Ceramic AB
    Inventor: Saeid Esmaeilzadeh
  • Patent number: 7244376
    Abstract: In hexaboride particles having particles of a hexaboride of at least one element (X) selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr and Ca, or a dispersion of such particles, the surfaces of the hexaboride particles have physically been coated with a surface treatment agent containing silicon, selected from a silazane type treatment agent, a chlorosilane type treatment agent, an inorganic treatment agent having at least one alkoxyl group in the molecular structure, and an organic treatment agent having at least one alkoxyl group at a molecular terminal or in the side chain, or have been coated with the surface treatment agent, having chemically combined with hexaboride particles on the surfaces of the hexaboride particles.
    Type: Grant
    Filed: January 26, 2004
    Date of Patent: July 17, 2007
    Assignee: Sumitomo Metal Mining Co., Ltd.
    Inventor: Hiromitsu Takeda
  • Patent number: 7192899
    Abstract: A silicon nitride sintered body exhibiting a high heat conductivity, the silicon nitride sintered body includes a rare earth element in an amount of 2 to 17.5 mass % in terms of the oxide thereof, Fe in an amount of 0.07 to 0.5 mass % in terms of the oxide thereof, Ca in an amount of 0.07 to 0.5 mass % in terms of the oxide thereof, Al in an amount of 0.1 to 0.6 mass % in terms of the oxide thereof, Mg in an amount of 0.3 to 4 mass % in terms of the oxide thereof, and Hf in an amount not larger than 5 mass % (including 0 mass %) in terms of the oxide thereof.
    Type: Grant
    Filed: February 9, 2006
    Date of Patent: March 20, 2007
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.
    Inventor: Michiyasu Komatsu
  • Patent number: 7157394
    Abstract: A silicon nitride based ceramic, that is highly effective for use as a cutting tool for the high speed machining of cast irons, that is essentially a homogeneous mixture consisting of both crystalline and whisker forms of beta silicon nitride that are interstitially bonded by a stoichiometrically balanced glass mixture of magnesia, silica, yttria and zirconia, where the ratios of each have been controlled to increase the eutectic point and refractoriness of the mixed glass.
    Type: Grant
    Filed: July 17, 2004
    Date of Patent: January 2, 2007
    Inventor: James Hugo Adams, Sr.
  • Patent number: 7056850
    Abstract: The present invention provides a wear resistant member composed of silicon nitride sintered body containing 2–10 mass % of rare earth element in terms of oxide thereof as sintering agent, 2–7 mass % of MgAl2O4 spinel, 1–10 mass % of silicon carbide, and 5 mass % or less of at least one element selected from the group consisting of Ti, Zr, Hf, W, Mo, Ta, Nb and Cr in terms of oxide thereof, wherein a porosity of said silicon nitride sintered body is 1 vol. % or less, a three-point bending strength is 900 MPa or more, and a fracture toughness is 6.3 MPa·m1/2 or more. According to the above structure of the present invention, there can be provided a silicon nitride wear resistant member and a method of manufacturing the member having a high strength and a toughness property, and particularly excellent in rolling and sliding characteristics.
    Type: Grant
    Filed: July 23, 2002
    Date of Patent: June 6, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Michiyasu Komatsu
  • Patent number: 6869902
    Abstract: A silicon nitride porous body (5) obtained by nitriding a molded body having metallic silicon (3) as a main component, the porous body having a porous structure with an average pore diameter of 3 ?m or above, and wherein the total content of silicon and nitrogen is 95% or above and the nitridation ratio of silicon is 90% or above. The silicon nitride porous body has a porous structure with a large average pore diameter, with a test specimen cut out from the porous body exhibiting large thermal conductivity and a small thermal expansion coefficient, and can be suitably used in a component for purifying gas and/or solution such as a ceramic filter.
    Type: Grant
    Filed: June 25, 2002
    Date of Patent: March 22, 2005
    Assignee: NGK Insulators, Ltd.
    Inventors: Katsuhiro Inoue, Kenji Morimoto, Masaaki Masuda, Shinji Kawasaki, Hiroaki Sakai
  • Patent number: 6861382
    Abstract: Sintered silicon nitride and a silicon nitride tool. The mean major axis length, the mean minor axis length, and the aspect ratio, represented by (mean major axis length/mean minor axis length) of constituent sintered silicon nitride grains in a silicon nitride tool are controlled, and the thermal conductivity and/or fracture toughness Kc thereof are enhanced, thereby providing a tool having a cutting edge which is not prone to chipping.
    Type: Grant
    Filed: November 18, 2002
    Date of Patent: March 1, 2005
    Assignee: NGK Spark Plug Co., Ltd.
    Inventor: Kohei Abukawa
  • Patent number: 6846764
    Abstract: A silicon nitride porous body which is obtained by nitriding a molded body having metallic silicon as a main component and by performing a high temperature heating treatment at a temperature higher than the nitriding temperature, and which has a porous structure with an average pore diameter of 3 ?m or above, and contains at least one kind of element selected from the group consisting of the groups 2A, 3A, 3B inclusive of lanthanoid elements, and 4B. The silicon nitride porous body has a porous structure with a large average pore diameter, a test specimen cut out from the porous body exhibiting a high thermal conductivity and a small thermal expansion coefficient, and can be suitably used in a component for purifying gas and/or solution such as a ceramic filter.
    Type: Grant
    Filed: March 25, 2002
    Date of Patent: January 25, 2005
    Assignee: NGK Insulators, Ltd.
    Inventors: Katsuhiro Inoue, Kenji Morimoto, Masaaki Masuda, Shinji Kawasaki, Hiroaki Sakai
  • Patent number: 6811868
    Abstract: The object of the present invention is to provide a ceramic body that can support a required amount of a catalyst component, without lowering the characteristics such as strength, being manufactured without forming a coating layer and providing a high performance ceramic catalyst that is excellent in practical utility and durability. A noble metal catalyst is supported directly on the surface of the ceramic body and the second component, consisting of compound or composite compound of element having d or f orbit in the electron orbits thereof such as W, Co, Ti, Fe, Ga and Nb, is dispersed in the first component made of cordierite or the like that constitutes the substrate ceramic. The noble metal catalyst can be directly supported by bonding strength generated by sharing the d or f orbits of the second component, or through interaction with the dangling bond that is generated in the interface between the first component and the second component.
    Type: Grant
    Filed: June 6, 2003
    Date of Patent: November 2, 2004
    Assignee: Denso Corporation
    Inventors: Jun Hasegawa, Tomomi Hase, Kazuhiko Koike, Miho Ito
  • Patent number: 6784131
    Abstract: The present invention provides a silicon nitride wear resistant member composed of silicon nitride sintered body containing 1-10 mass % of rare earth element in terms of oxide thereof as sintering agent, wherein a total oxygen content of the silicon nitride sintered body is 6 mass % or less, a porosity of the silicon nitride sintered body is 0.5 vol. % or less, and a maximum size of pore existing in grain boundary phase of the silicon nitride sintered body is 0.3 &mgr;m or less. According to the above structure of the present invention, there can be provided a silicon nitride wear resistant member and a method of manufacturing the member having a high strength and a toughness property, and particularly excellent in sliding characteristics.
    Type: Grant
    Filed: January 11, 2002
    Date of Patent: August 31, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Michiyasu Komatsu, Hiroki Tonai, Hiroshi Komorita
  • Patent number: 6749930
    Abstract: A corrosion-resistive member is provided, including a corrosion-resistive face that is exposed to a corrosive gas causing ion bombardmemt. At least a part of the corrosion-resistive member is composed of a sintered silicon nitride body having an open porosity of not more than 5%. The sintered silicon nitride body constitutes the corrosion-resistive face, and if two auxiliary planes are formed by cutting the corrosion-resistive member to intersect vertically with the corrosion-resistive face and to be located vertically with respect to each other, the orientation index between the two auxiliary planes is in a range of 0.8 to 1.2, and the orientation index between the corrosion-resistive face and each of the auxiliary faces is at least 1.5.
    Type: Grant
    Filed: October 18, 2001
    Date of Patent: June 15, 2004
    Assignee: NGK Insulators, Ltd.
    Inventor: Tsuneaki Ohashi
  • Publication number: 20040009866
    Abstract: Sintered silicon nitride containing silicon nitride substantially as a primary component and containing substantially no Al2O3. The sintered silicon nitride further contains at least one element selected from among a Group 4 element of the periodic table, a rare earth element and Mg. The amount of the selected element as converted to its oxide is at least 0.5 mol % and less than 2.6 mol % based on the entirety of the sintered silicon nitride. Also disclosed is a cutting tip, a wear-resistant member, a cutting tool and a method for producing the sintered silicon nitride.
    Type: Application
    Filed: June 12, 2003
    Publication date: January 15, 2004
    Applicant: NGK SPARK PLUG CO. LTD.
    Inventors: Kohei Abukawa, Yasushi Akahori
  • Patent number: 6670294
    Abstract: 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: Grant
    Filed: January 23, 2002
    Date of Patent: December 30, 2003
    Assignee: NGK Insulators, Ltd.
    Inventor: Hiromichi Kobayashi
  • Patent number: 6599637
    Abstract: A Si3N4 composite substrate which manifests no generation of cracking on the substrate even by mechanical shock or thermal shock, and is excellent in heat radiation property and heat-cycle-resistance property is obtained by using a Si3N4 substrate as a ceramic substrate. A Si3N4 substrate having a thermal conductivity of 90 W/m·K or more and a three-point flexural strength of 700 MPa or more is used, and the thickness tm of a metal layer connected on one major surface of the substrate and the thickness tc of the Si3N4 substrate are controlled so as to satisfy the relation formula: 2 tm≦tc≦20 tm. When metal layers are connected to both major surfaces of the Si3N4 substrate, the thickness tc and the total thickness ttm of the metal layers on both major surfaces are controlled so as to satisfy the relation formula: ttm≦tc≦10 ttm.
    Type: Grant
    Filed: April 24, 2001
    Date of Patent: July 29, 2003
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Ai Itoh, Michimasa Miyanaga, Masashi Yoshimura
  • Patent number: 6592782
    Abstract: Metal oxides particularly useful for the manufacture of catalytic membranes for gas-phase oxygen separation processes having the formula: AxA′x′A″2-(x+x′)ByFey′B″2-(y+y′)O5+z where: x and x′ are greater than 0; y and y′ are greater than 0; x+x′ is equal to 2; y+y′ is less than or equal to 2; z is a number that makes the metal oxide charge neutral; A is an element selected from the lanthanide elements; A′ is an element selected from Be, Mg, Ca, Sr, Ba and Ra; A″ is an element selected from the f block lanthanides, Be, Mg, Ca, Sr, Ba and Ra; B is an element selected from the group consisting of Al, Ga, In or mixtures thereof and B″ is Co or Mg, with the exception that when B″ is Mg, A′ and A″ are not Mg. The metal oxides are useful for preparation of dense membranes which may be formed from dense thin films of the mixed metal oxide on a porous metal oxide element.
    Type: Grant
    Filed: December 22, 2000
    Date of Patent: July 15, 2003
    Assignee: Eltron Research, Inc.
    Inventors: Richard MacKay, Michael Schwartz, Anthony F. Sammells
  • Publication number: 20030100434
    Abstract: A low-thermal-expansion, rigid and wear-resistant ceramic is provided.
    Type: Application
    Filed: October 8, 2002
    Publication date: May 29, 2003
    Inventors: Yasuki Yoshitomi, Tadahisa Arahori
  • Publication number: 20030096695
    Abstract: Sintered silicon nitride and a silicon nitride tool. The mean major axis length, the mean minor axis length, and the aspect ratio, represented by (mean major axis length/mean minor axis length) of constituent sintered silicon nitride grains in a silicon nitride tool are controlled, and the thermal conductivity and/or fracture toughness Kc thereof are enhanced, thereby providing a tool having a cutting edge which is not prone to chipping.
    Type: Application
    Filed: November 18, 2002
    Publication date: May 22, 2003
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventor: Kohei Abukawa
  • Patent number: 6534430
    Abstract: A sensor material for measuring physical parameters capable of configuring a sensor capable of directly measuring a high value of physical parameters such as high stress or high pressure without employing a pressure resistance container. The sensor material for measuring static and dynamic physical parameters includes a matrix made of an electrically insulating ceramic material, and piezoresistance materials which are dispersed in the matrix so as to be electrically continuous to each other.
    Type: Grant
    Filed: February 27, 2001
    Date of Patent: March 18, 2003
    Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho
    Inventors: Hiroaki Makino, Mitsuru Asai, Nobuo Kamiya, Shin Tajima, Katsunori Yamada, Hiroshi Hohjo
  • Patent number: 6458732
    Abstract: 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: Grant
    Filed: June 7, 1999
    Date of Patent: October 1, 2002
    Assignee: Allied Mineral Products, Inc.
    Inventors: Douglas K. Doza, John Y. Liu
  • Patent number: 6432855
    Abstract: A ceramic material which is an orthorhombic boride of the general formula: AlMgB14:X, with X being a doping agent. The ceramic is a superabrasive, and in most instances provides a hardness of 40 GPa or greater.
    Type: Grant
    Filed: May 23, 2000
    Date of Patent: August 13, 2002
    Assignee: Iowa State University Reseach Foundation, Inc,.
    Inventors: Bruce A. Cook, Joel L. Harringa, Alan M. Russell
  • Patent number: 6410468
    Abstract: A slurry Si-base composition comprising an Si powder having a thickness of a surface oxide film ranging from 1.5 to 15 nm, 50 to 90% by weight of water, 0.2 to 7.5% by weight, in terms of oxide, of a sintering aid and 0.05 to 3% by weight of a dispersant, the Si-base composition having a pH value adjusted to 8-12. This slurry Si-base composition is produced by a process which comprises subjecting Si powder to oxidation treatment at 200 to 800° C. in air, adding 50 to 90% by weight of water, 0.2 to 7.5% by weight, in terms of oxide, of a sintering aid and 0.05 to 3% by weight of a dispersant to the oxidized Si powder and performing such a pH adjustment that the resultant mixture has a pH value of 8 to 12. The slurry Si-base composition not only enables producing a ceramic of Si3N4 at a lowered cost without the need to install explosionproof facilities but also allows the obtained Si3N4 ceramic having a relative density of at least 96% and a flexural strength of at least 800 MPa can be obtained.
    Type: Grant
    Filed: July 5, 2001
    Date of Patent: June 25, 2002
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Seiji Nakahata, Akira Yamakawa
  • Patent number: 6395661
    Abstract: A sintered Si3N4 material, valves and components made with the material, and methods for making same.
    Type: Grant
    Filed: October 4, 1999
    Date of Patent: May 28, 2002
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gerhard Wötting, Ernst Gugel, Hans Andreas Lindner, Peter Woditsch
  • Patent number: 6391812
    Abstract: A method of producing the silicon nitride sintered body includes the steps of forming a compact of molding materials including silicon nitride powder, a Mg component and a sintering aid, and sintering the molding materials at 1,800 to 2,000° C. under a nitrogen atmosphere. The materials at least include an oxide of Mg in a range of 0.3 to 10 wt. %. A constant temperature is kept for at least 0.5 hours in a temperature range of 1,400 to 1,700° C. before the temperature is increased to the sintering temperature. A silicon nitride body having high thermal conductivity and excellent electrical insulation properties at high temperature can thus be provided.
    Type: Grant
    Filed: May 26, 2000
    Date of Patent: May 21, 2002
    Assignee: NGK Insulators, Ltd.
    Inventors: Kiyoshi Araki, Katsuhiro Inoue
  • Patent number: 6313054
    Abstract: The present invention provides a silicon nitride sintered body having characteristics such as excellent wear resistance, a method for manufacturing the sintered body, and a cutting insert formed thereof. The silicon nitride sintered body is formed of a polycrystalline sintered body of predominantly &bgr;-Si3N4, wherein the oxygen content is 1.2-1.5 wt. %. The method for manufacturing the silicon nitride sintered body includes the following steps: adding an organic binder to a composition containing silicon nitride as an essential component and exhibiting a theoretical oxygen content of 2.0-3.0 wt. %; heating to remove the binder; introducing an oxygen-containing gas so as to control the carbon content to 0.10-0.60 wt. %; and sintering a resultant compact in an nitrogen atmosphere to control the oxygen content to 1.2-1.5 wt. %. The cutting insert of the present invention has excellent wear resistance.
    Type: Grant
    Filed: August 14, 2000
    Date of Patent: November 6, 2001
    Assignee: NGK Spark Plug Co., Ltd.
    Inventor: Masaru Matsubara
  • Patent number: 6294244
    Abstract: A wiring board of the present invention is equipped with an insulating board formed of a sintered product of silicon nitride containing a silicon nitride crystal phase, and a metal circuit formed on said insulating board, wherein said sintered product of silicon nitride contains a rare earth element (RE) and magnesium in a total amount of from 4 to 30 mol % calculated as oxides and at a molar ratio (RE2O3/MgO) calculated as oxides of from 0.1 to 15, and has a relative density of not smaller than 90% and a heat conductivity of not smaller than 50 W/m·K. The wiring board is equipped with the insulating board having very excellent heat-radiating property and a large strength, and is very useful as a wiring board for, for example, power modules.
    Type: Grant
    Filed: December 21, 1998
    Date of Patent: September 25, 2001
    Assignee: Kyocera Corporation
    Inventors: Toshihiro Iwaida, Teruhisa Makino, Masanobu Ishida, Tomohide Hasegawa, Hirosi Okayama