Patents by Inventor Tomohisa Arai
Tomohisa Arai has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20120097297Abstract: There are provided a high hardness, high corrosion resistance and high wear resistance alloy, wherein the alloy is an aging heat treated Cr(chromium)-Al(aluminum)-Ni(nickel)-base alloy, the proportion of a mixed phase of (? phase+?? phase+? phase) precipitated at grain boundaries of ? phase grains in a metal structure in the cross section of the alloy is not less than 95% in terms of area ratio, and the intensity ratio as measured by X-ray diffractometry of the alloy is not less than 50% and not more than 200% in terms of I?(110)/[I?(200)+I??(004)]×100, and a component comprising this alloy, a material for an alloy which can form this alloy, and a process for producing this alloy. The present invention can provide a Cr—Al—Ni-base alloy possessing excellent corrosion resistance, hardness, wear resistance, releasability, fatigue strength, and planishing property in a molding face, a component comprising this alloy, a material for an alloy which can form this alloy, and a process for producing this alloy.Type: ApplicationFiled: September 22, 2011Publication date: April 26, 2012Applicants: Toshiba Materials Co., Ltd., Kabushiki Kaisha ToshibaInventors: Takashi Rokutanda, Tomohisa Arai, Takao Kusaka, Nobuyoshi Jimbo
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Patent number: 8062441Abstract: There are provided a high hardness, high corrosion resistance and high wear resistance alloy, wherein the alloy is an aging heat treated Cr(chromium)-Al(aluminum)-Ni(nickel)-base alloy, the proportion of a mixed phase of (? phase+?? phase+? phase) precipitated at grain boundaries of ? phase grains in a metal structure in the cross section of the alloy is not less than 95% in terms of area ratio, and the intensity ratio as measured by X-ray diffractometry of the alloy is not less than 50% and not more than 200% in terms of I?(110)/[I?(200)+I??(004)]×100, and a component comprising this alloy, a material for an alloy which can form this alloy, and a process for producing this alloy. The present invention can provide a Cr—Al—Ni-base alloy possessing excellent corrosion resistance, hardness, wear resistance, releasability, fatigue strength, and planishing property in a molding face, a component comprising this alloy, a material for an alloy which can form this alloy, and a process for producing this alloy.Type: GrantFiled: September 22, 2005Date of Patent: November 22, 2011Assignees: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.Inventors: Takashi Rokutanda, Tomohisa Arai, Takao Kusaka, Nobuyoshi Jimbo
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Publication number: 20100211048Abstract: Disclosed is a medical guide wire that can realize improved insertability and imaging properties. The medical guide wire comprises a medical guide wire main body part comprising a body part and a frontal end part having a smaller wire diameter than the body part, and a coil part and a cap part provided at the frontal end part. The coil part comprises a wire which is a clad wire comprising a core part that is composed mainly of at least one of tungsten and molybdenum and a covering part that covers the core part and is composed mainly of titanium.Type: ApplicationFiled: September 19, 2008Publication date: August 19, 2010Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.Inventors: Tomohisa Arai, Fumihiko Yoshimura
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Patent number: 7740719Abstract: A cutter is composed of a Ni—Cr alloy containing from 32 to 44 mass percent of Cr, from 2.3 to 6.0 mass percent of Al, the balance being Ni, impurities, and additional trace elements and having a Rockwell C hardness of 52 or more. This Ni—Cr alloy provides a cutter produced with a superior workability and by a significantly simplified process, having a low deterioration in the hardness even when heated in use, having excellent corrosion resistance and low-temperature embrittlement resistance, and satisfactorily maintaining the cutting performance for a long time.Type: GrantFiled: May 14, 2003Date of Patent: June 22, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Tomohisa Arai, Takashi Rokutanda, Tadaharu Kido
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Patent number: 7682474Abstract: A cutter is composed of a Ni—Cr—Al alloy containing from 32 to 44 mass percent of Cr, from 2.3 to 6.0 mass percent of Al, the balance being Ni, impurities, and additional trace elements and having a Rockwell C hardness of 52 or more. This Ni—Cr—Al alloy provides a cutter produced with a superior workability and by a significantly simplified process, having a low deterioration in the hardness even when heated in use, having excellent corrosion resistance and low-temperature embrittlement resistance, and satisfactorily maintaining the cutting performance for a long time.Type: GrantFiled: August 4, 2008Date of Patent: March 23, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Tomohisa Arai, Takashi Rokutanda, Tadaharu Kido
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Publication number: 20080302449Abstract: A cutter is composed of a Ni—Cr alloy containing from 32 to 44 mass percent of Cr, from 2.3 to 6.0 mass percent of Al, the balance being Ni, impurities, and additional trace elements and having a Rockwell C hardness of 52 or more. This Ni—Cr alloy provides a cutter produced with a superior workability and by a significantly simplified process, having a low deterioration in the hardness even when heated in use, having excellent corrosion resistance and low-temperature embrittlement resistance, and satisfactorily maintaining the cutting performance for a long time.Type: ApplicationFiled: August 4, 2008Publication date: December 11, 2008Inventors: Tomohisa ARAI, Takashi Rokutanda, Tadaharu Kido
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Publication number: 20080121319Abstract: There are provided a high hardness, high corrosion resistance and high wear resistance alloy, wherein the alloy is an aging heat treated Cr(chromium)-Al(aluminum)-Ni(nickel)-base alloy, the proportion of a mixed phase of (? phase+?? phase+? phase) precipitated at grain boundaries of ? phase grains in a metal structure in the cross section of the alloy is not less than 95% in terms of area ratio, and the intensity ratio as measured by X-ray diffractometry of the alloy is not less than 50% and not more than 200% in terms of I?(110)/[I?(200)+I??(004)]×100, and a component comprising this alloy, a material for an alloy which can form this alloy, and a process for producing this alloy. The present invention can provide a Cr—Al—Ni-base alloy possessing excellent corrosion resistance, hardness, wear resistance, releasability, fatigue strength, and planishing property in a molding face, a component comprising this alloy, a material for an alloy which can form this alloy, and a process for producing this alloy.Type: ApplicationFiled: September 22, 2005Publication date: May 29, 2008Inventors: Takashi Rokutanda, Tomohisa Arai, Takao Kusaka, Nobuyoshi Jimbo
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Publication number: 20050172991Abstract: A thermoelectric element (1) comprises N type thermoelectric semiconductors (4) and P type thermoelectric semiconductors (5) arranged between support members (2, 3). The N type and P type thermoelectric semiconductors (4, 5) are connected together in series by heat absorbing electrodes (6) and heat radiating electrodes (7) joined to the ends of these semiconductors. First heat transmitting members (8) are integrally provided to the heat radiating electrodes (7), and second heat transmitting members (9) are integrally provided to the heat absorbing electrodes (6) and are allowed to protrude in the same direction as (in a direction opposite to) the direction of the first heat transmitting members (8). The second heat transmitting members (9) function as heat radiating media when the thermoelectric element (1) is not in operation to dissipate the heat of a component (16) to be cooled into a radiation space via the second heat transmitting members (9).Type: ApplicationFiled: June 18, 2003Publication date: August 11, 2005Inventors: Tomohisa Arai, Takashi Rokutanda, Masami Okamura
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Publication number: 20050167010Abstract: A cutter is composed of a Ni—Cr alloy containing from 32 to 44 mass percent of Cr, from 2.3 to 6.0 mass percent of Al, the balance being Ni, impurities, and additional trace elements and having a Rockwell C hardness of 52 or more. This Ni—Cr alloy provides a cutter produced with a superior workability and by a significantly simplified process, having a low deterioration in the hardness even when heated in use, having excellent corrosion resistance and low-temperature embrittlement resistance, and satisfactorily maintaining the cutting performance for a long time.Type: ApplicationFiled: May 14, 2003Publication date: August 4, 2005Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Tomohisa Arai, Takashi Rokutanda, Tadaharu Kido
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Patent number: 6546968Abstract: A bond magnet comprises a molded body in which a mixture of flake of magnet material comprising rare earth element-iron-nitrogen as main component, TbCu7 type crystal phase as a principal phase and a thickness of less than 200 &mgr;m a binder is compression molded. A compression molded body constituting a bond magnet has a density of 6×103 kg/m3 or more. In the step of compression molding a mixture of magnet material and binder, pressure is applied a plurality of times, or pressure is applied while rotating a punch and die, or the binder is cured while applying pressure to obtain such a bond magnet with good reproducibility. Such a bond magnet has excellent magnetic properties and corrosion resistance.Type: GrantFiled: August 22, 2001Date of Patent: April 15, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Katsutoshi Nakagawa, Fumiyuki Kawashima, Takao Sawa, Shinya Sakurada, Tomohisa Arai
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Publication number: 20020195172Abstract: Giant magnetostrictive material, with an alloy including a rare earth element and a transition metal element, is obtained by dissolving nitrogen interstitially in the alloy. Nitrogen is introduced in the alloy in the range from 0.01 to 2.5% by mass. Nitrogen introducing treatment is carried out at a temperature of 600° C. or less. A content of nitrogen compound present in magnetostrictive alloy, by a ratio of a content of nitrogen in the nitrogen compound to a total nitrogen content in the alloy, is reduced to be 0.05 or less by mass ratio. Almost all of the added nitrogen is interstitially dissolved between crystal lattice. In giant magnetostrictive material using melt quench flakes, the flakes are stacked in a thickness direction that is a direction of growth of columnar grain essentially constituting the flake material to integrate in this state.Type: ApplicationFiled: July 31, 2002Publication date: December 26, 2002Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Tomohisa Arai, Hideki Yamamiya, Masami Okamura, Tadahiko Kobayashi
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Patent number: 6467277Abstract: A cold accumulating material comprising a number of magnetic particles mainly composed of oxide, wherein an average value of equivalent circle diameters of crystal grains constituting the magnetic particles is 0.3-20 &mgr;m. It is preferable that an area ratio of the crystal grains each having an equivalent circle diameter of 50 &mgr;m or more is 10% or less with respect to whole crystal grains constituting the magnetic particle. According to the above structure, there can be provided a cold accumulating material which is free from being finely pulverized, and is excellent in thermal shock resistance and durability, and capable of exhibiting a significant refrigerating performance at low temperature range for a long period of time in a stable condition.Type: GrantFiled: July 18, 2001Date of Patent: October 22, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Masami Okamura, Tomohisa Arai
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Patent number: 6468440Abstract: Magnet powder has a composition expressed by (R1XR2YBZT100−X−Y−Z)100−QNQ (in formula, R1 is at least one kind of element selected from rare earth elements, R2 is at least one kind of element selected from Zr, Hf and Sc, T is at least one kind of element selected from Fe and Co, and X, Y, Z and Q are numbers satisfying 2 atomic %≦X, 0.01 atomic %≦Y, 4≦X+Y≧20 atomic %, 0≦Z≦10 atomic %, and 0.1≦Q≦20 atomic %, respectively), and TbCu7 crystal phase as a principal phase. In such magnet powder, a ratio of fine particles of which maximum diameter is 22 &mgr;m or less is 20% by weight or less. Alternatively, surface roughness of particles constituting the magnet powder is 5 &mgr;m or less in terms of maximum height Ry provided in JIS B 0601-1994. Accordingly, to such a magnet powder, excellent magnetic properties can be obtained with reproducibility.Type: GrantFiled: September 22, 2000Date of Patent: October 22, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Shinya Sakurada, Tomohisa Arai, Masami Okamura, Keisuke Hashimoto, Takahiro Hirai
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Patent number: 6460348Abstract: A regenerator comprises a regenerator body and cold accumulating material packed in the regenerator body in which cooling medium gas flows from one end portion of the regenerator body to the other end portion of the regenerator body so as to obtain a lower temperature, wherein at least part of the cold accumulating material is a plate-shaped cold accumulating material having a thickness of 0.03-2 mm. In the above structure, it is preferable that the cold accumulating material is composed of an alloy containing 10 at % or more of rare earth element and that a length of the plate-shaped cold accumulating material in a flowing direction of the cooling medium gas is 1-100 mm.Type: GrantFiled: March 22, 2001Date of Patent: October 8, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Masami Okamura, Tomohisa Arai
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Patent number: 6416593Abstract: A magnetic material has a composition expressed by the following general formula, general formula: {(R1XR21-X)YBZT1-Y-Z}1-QNQ (where, R1 is at least one kind of element selected from rare earth elements, R2 is at least one kind of element selected from Zr, Hf, Ti and Sc, T is at least one kind of element selected from Fe and Co, and X, Y, Z and Q designate numerical values satisfying 0.5≦X<1, 0.05≦Y≦0.2, 0≦Z≦0.1 and 0.1≦Q≦0.2), and includes 5 volume % or more of a Th2Ni17 crystal phase. The magnetic material has a recrystallization texture of which average grain diameter is in the range of from 0.02 to 50 &mgr;m, and is excellent in magnetic property. Such a magnetic material is obtained by giving a HDDR treatment to a mother alloy of which principal phase is a Th2Ni17 crystal phase.Type: GrantFiled: August 16, 2001Date of Patent: July 9, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Shinya Sakurada, Tomohisa Arai, Masami Okamura, Keisuke Hashimoto, Takahiro Hirai
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Patent number: 6406559Abstract: A magnetic material essentially consists of a composition represented by general formula: R1XR2YBZNUHVM100-X-Y-Z-C-V (in the formula, R1 denotes at least one kind element selected from rare earth elements, R2 denotes at least one kind element selected from Zr, Hf and Sc, M denotes at least one kind element selected from Fe and Co, X, Y, Z, U and V are numbers satisfying 2 at. %≦X, 0.01 at. %≦Y, 4≦X+Y≦20 at. %, 0≦Z≦10 at. %, 0.1≦U≦18 at. %, 0.01≦V≦10 at. %, respectively), and comprises a TbCu7 type crystal phase as a principal phase. A nitriding treatment to a mother alloy is carried out in a mixed gas of ammonia gas and hydrogen gas of which partial pressure ratio is set in the range of 3<Py/Px when partial pressure of ammonia gas is PX, that of the hydrogen gas is Py.Type: GrantFiled: July 13, 2001Date of Patent: June 18, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Shinya Sakurada, Takahiro Hirai, Keisuke Hashimoto, Tomohisa Arai
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Patent number: 6363727Abstract: A cold accumulating material comprises a set of particulate cold accumulating substances, pores formed between the particulate cold accumulating substances, and a binder for mutually binding the particulate cold accumulating substances, wherein a porosity of the cold accumulating material is 15-70 vol %. A median diameter of the pores existing in the cold accumulating material is preferably set to 10-300 &mgr;m. An oxygen concentration at an area ranging from a surface of the particulate cold accumulating substance to a portion having a depth of 100 angstroms (A) from the surface is preferably set to 5-80 at %.Type: GrantFiled: December 22, 1999Date of Patent: April 2, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Keisuke Hashimoto, Masami Okamura, Tomohisa Arai
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Publication number: 20020036558Abstract: A bond magnet comprises a molded body in which a mixture of flake of magnet material comprising rare earth element-iron-nitrogen as main component, TbCu7 type crystal phase as a principal phase and a thickness of less than 200 &mgr;m a binder is compression molded. A compression molded body constituting a bond magnet has a density of 6×103 kg/m3 or more. In the step of compression molding a mixture of magnet material and binder, pressure is applied a plurality of times, or pressure is applied while rotating a punch and die, or the binder is cured while applying pressure to obtain such a bond magnet with good reproducibility. Such a bond magnet has excellent magnetic properties and corrosion resistance.Type: ApplicationFiled: August 22, 2001Publication date: March 28, 2002Inventors: Katsutoshi Nakagawa, Fumiyuki Kawashima, Takao Sawa, Shinya Sakurada, Tomohisa Arai
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Publication number: 20020026799Abstract: A cold accumulating material comprising a number of magnetic particles mainly composed of oxide, wherein an average value of equivalent circle diameters of crystal grains constituting the magnetic particles is 0.3-20 &mgr;m. It is preferable that an area ratio of the crystal grains each having an equivalent circle diameter of 50 &mgr;m or more is 10% or less with respect to whole crystal grains constituting the magnetic particle. According to the above structure, there can be provided a cold accumulating material which is free from being finely pulverized, and is excellent in thermal shock resistance and durability, and capable of exhibiting a significant refrigerating performance at low temperature range for a long period of time in a stable condition.Type: ApplicationFiled: July 18, 2001Publication date: March 7, 2002Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Masami Okamura, Tomohisa Arai
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Publication number: 20020011279Abstract: A magnetic material has a composition expressed by the following general formula,Type: ApplicationFiled: August 16, 2001Publication date: January 31, 2002Inventors: Shinya Sakurada, Tomohisa Arai, Masami Okamura, Keisuke Hashimoto, Takahiro Hirai