Patents by Inventor Akihiko Chiba
Akihiko Chiba 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: 20210083182Abstract: A semiconductor memory device includes first and second wirings extending in a first direction and spaced apart from each other in the first direction, third wirings above the first and second wirings and extending in a second direction, fourth and fifth wirings above the third wirings, extending in the first direction, and spaced apart from each other in the second direction, a plurality of memory cells between each third wiring and each of first, second, fourth, and fifth wirings, voltage application circuits, connection conductors between the voltage application circuits and the wirings, and connection wirings that electrically connect the fourth and fifth wirings to the voltage application circuits. The voltage application circuits are arranged so that a non-selected voltage application circuit is under a space between the first and second wirings, and a selected voltage application circuit is under the first wiring.Type: ApplicationFiled: February 27, 2020Publication date: March 18, 2021Inventors: Hiroyuki HARA, Hiroyuki TAKENAKA, Akihiko CHIBA
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Publication number: 20210039192Abstract: A production method of an additive manufactured object according to an EB-based additive manufacturing method of spreading a pure copper powder, preheating the pure copper powder and thereafter partially melting the pure copper powder by scanning the pure copper powder with an electron beam, solidifying the pure copper powder to form a first layer, newly spreading a pure copper powder on the first layer, preheating the pure copper powder and thereafter partially melting the pure copper powder by scanning the pure copper powder with an electron beam, solidifying the pure copper powder to form a second layer, and repeating the foregoing process to add layers, wherein used as the pure copper powder is a pure copper powder with a Si coating formed thereon, and wherein the preheating temperature is set to be 400° C. or higher and less than 800° C.Type: ApplicationFiled: December 26, 2019Publication date: February 11, 2021Inventors: Hirofumi Watanabe, Hiroyoshi Yamamoto, Yoshitaka Shibuya, Kenji Sato, Satoru Morioka, Akihiko Chiba, Kenta Aoyagi
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Patent number: 10808306Abstract: Provided is a Co—Ni-based alloy in which a crystal is easily controlled, a method of controlling a crystal of a Co—Ni-based alloy, a method of producing a Co—Ni-based alloy, and a Co—Ni-based alloy having controlled crystallinity. The Co—Ni-based alloy includes Co, Ni, Cr, and Mo, in which the Co—Ni-based alloy has a crystal texture in which a Goss orientation is a main orientation. The Co—Ni-based alloy preferably has a composition including, in terms of mass ratio: 28 to 42% of Co, 10 to 27% of Cr, 3 to 12% of Mo, 15 to 40% of Ni, 0.1 to 1% of Ti, 1.5% or less of Mn, 0.1 to 26% of Fe, 0.1% or less of C, and an inevitable impurity; and at least one kind selected from the group consisting of 3% or less of Nb, 5% or less of W, 0.5% or less of Al, 0.1% or less of Zr, and 0.01% or less of B.Type: GrantFiled: December 11, 2015Date of Patent: October 20, 2020Assignees: SEIKO INSTRUMENTS INC., TOHOKU UNIVERSITYInventors: Akihiko Chiba, Takuma Otomo, Yasunori Akasaka, Tomoo Kobayashi, Ryo Sugawara
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Patent number: 10787725Abstract: An object of the invention is to provide: an HEA article that has excellent homogeneity in the alloy composition and microstructure as well as significant shape controllability, using an HEA with significant mechanical strength and high corrosion resistance; a method for manufacturing the HEA article; and a product using the HEA article. There is provided an HEA article comprising: Co, Cr, Fe, Ni, and Ti elements, each element in content of 5 to 35 atomic %; more than 0 atomic % to 8 atomic % of Mo %; and remainder substances of unavoidable impurities.Type: GrantFiled: November 8, 2016Date of Patent: September 29, 2020Assignee: Hitachi Metals, Ltd.Inventors: Tadashi Fujieda, Kousuke Kuwabara, Mamoru Hirota, Kinya Aota, Takahiko Kato, Akihiko Chiba, Yuichiro Koizumi, Kenta Yamanaka
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Publication number: 20200277687Abstract: Provided is a heat-resistant titanium (Ti) alloy member having excellent mechanical characteristics and oxidation resistance at high temperatures and having less mechanical anisotropy, a method for producing such a titanium alloy member, and a product including such an alloy member. A titanium-based alloy member includes titanium (Ti) as a major element and at least 0.5 to 2.0 mass % of boron (B) and has a dispersion of fiber-like TiB particles precipitated in a polycrystal matrix phase, the TiB particles each having a long axis of 1 to 10 ?m and a short axis of 0.01 to 0.5 ?m or less and having an aspect ratio of 2 to 1000, the TiB particles precipitating in a crystallographically random direction in each of crystal grains of the matrix phase.Type: ApplicationFiled: October 11, 2018Publication date: September 3, 2020Applicants: HITACHI, LTD., TOHOKU UNIVERSITYInventors: Tadashi FUJIEDA, Kousuke KUWABARA, Atsuhiko OONUMA, Akihiko CHIBA, Yuichiro KOIZUMI, Kenta YAMANAKA
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Patent number: 10513757Abstract: Provided is a corrosion-resistant, high-hardness alloy composition, which realizes both corrosion resistance and high hardness by using a Ni—Co—Cr—Mo-based alloy and optimizing the chemical composition, heat treatment conditions and processing conditions thereof, and a method for producing that alloy composition. The alloy composition is an alloy composition comprising 15.5% by weight to 16.5% by weight of Cr, 7.5% by weight to 15.5% by weight of Mo, 0% by weight to 30% by weight of Co, 4.5% by weight to 15% by weight of Fe and 0.5% by weight to 4.0% by weight of Cu, with the remainder consisting of Ni and unavoidably included elements, wherein the crystal phase consists only of a 7 phase and the Vickers hardness at room temperature is 500 HV or more. The alloy composition is obtained by subjecting an ingot of an alloy having the aforementioned composition to homogenization treatment for 4 hours to 24 hours at 1100° C. to 1300° C.Type: GrantFiled: August 5, 2014Date of Patent: December 24, 2019Assignees: TOHOKU UNIVERSITY, KABUSHIKA KAISHA EIWAInventors: Yunping Li, Akihiko Chiba
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Publication number: 20190352730Abstract: A microalloyed steel component according to an aspect of the present disclosure includes a structure composed of ferrite and pearlite. The microalloyed steel component includes a columnar structure including band-shaped pearlite layers extending in a longitudinal direction of the microalloyed steel component and having a width of 200 ?m or shorter, and a ferrite layer precipitated so as to extend in the longitudinal direction between the pearlite layers.Type: ApplicationFiled: April 18, 2019Publication date: November 21, 2019Applicants: TOHOKU UNIVERSITY, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Akihiko CHIBA, Kenta AOYAGI, Chikatoshi MAEDA, Toshihiro MOURI
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Publication number: 20190047049Abstract: An object of the invention is to provide: an alloy article that has excellent homogeneity in the alloy composition and microstructure as well as significant shape controllability, using an HEA with significant mechanical strength and high corrosion resistance; a method for manufacturing the alloy article; and a product using the alloy article. There is provided an alloy article comprising: Co, Cr, Fe, Ni, and Ti elements, each element in content of 5 to 35 atomic %; more than 0 atomic % to 8 atomic % of Mo %; and remainder substances of unavoidable impurities. And, ultrafine particles with an average diameter of 40 nm or less are dispersedly precipitated in matrix phase crystals of the alloy article.Type: ApplicationFiled: October 25, 2016Publication date: February 14, 2019Applicant: HITACHI METALS, LTD.Inventors: Tadashi FUJIEDA, Mamoru HIROTA, Kosuke KUWABARA, Kinya AOTA, Takahiko KATO, Akihiko CHIBA, Yuichiro KOIZUMI, Kenta YAMANAKA, Seiichi WATANABE
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Patent number: 10196724Abstract: A method for manufacturing a Ni-based super-heat-resistant alloy includes: a first cold working step for cold working a Ni-based super-heat-resistant alloy ingot, which has a composition in which the ?? mole ratio is at least 40%, at a working ratio of 5% to less than 30%; and a first heat treatment step for heat-treating the cold worked material, on which the first cold working was performed, at a temperature exceeding the ?? solid solution temperature. It is preferable that the manufacturing method also includes a second cold working step for performing, after the first heat treatment step, a second cold working on the heat-treated material at a working ratio of at least 20%, and a second heat treatment step for heat-treating the second cold worked material, on which the second cold working has been performed, at less than the ?? solvus temperature.Type: GrantFiled: February 3, 2016Date of Patent: February 5, 2019Assignees: HITACHI METALS, LTD., TOHOKU UNIVERSITYInventors: Gang Han, Koji Sato, Tomonori Ueno, Akihiko Chiba
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Publication number: 20180363104Abstract: An object of the invention is to provide: an HEA article that has excellent homogeneity in the alloy composition and microstructure as well as significant shape controllability, using an HEA with significant mechanical strength and high corrosion resistance; a method for manufacturing the HEA article; and a product using the HEA article. There is provided an HEA article comprising: Co, Cr, Fe, Ni, and Ti elements, each element in content of 5 to 35 atomic %; more than 0 atomic % to 8 atomic % of Mo %; and remainder substances of unavoidable impurities.Type: ApplicationFiled: November 8, 2016Publication date: December 20, 2018Applicant: HITACHI METALS, LTD.Inventors: Tadashi FUJIEDA, Kousuke KUWABARA, Mamoru HIROTA, Kinya AOTA, Takahiko KATO, Akihiko CHIBA, Yuichiro KOIZUMI, Kenta YAMANAKA
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Publication number: 20180333775Abstract: The present invention relates to a metal powder which shortens a lamination-shaping time and facilitates the removal of an unnecessary powder after lamination-shaping by decreasing a pre-sintering temperature by using a processed metal powder. This metal powder for lamination-shaping is obtained by coating the surface of a powder of a nickel-based alloy with a conductive material. When the powder is the powder of the nickel-based alloy containing nickel as a main component and chromium and iron as primary subcomponents, the powder is coated, e.g., plated with nickel as the conductive material. The particle diameter range of the powder of the nickel-based alloy is 10 to 200 ?m, preferably 25 to 150 ?m, and more preferably 45 to 105 ?m. The thickness range of the conductive material is 0.1 to 1 ?m, and preferably 0.3 ?m or more.Type: ApplicationFiled: December 26, 2016Publication date: November 22, 2018Applicant: Technology Research Association For Future Additive ManufacturingInventors: Motonori NISHIDA, Yuji SUGITANI, Akihiko CHIBA, Youhei DAINO
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Publication number: 20180023176Abstract: A method for manufacturing a Ni-based super-heat-resistant alloy includes: a first cold working step for cold working a Ni-based super-heat-resistant alloy ingot, which has a composition in which the ?? mole ratio is at least 40%, at a working ratio of 5% to less than 30%; and a first heat treatment step for heat-treating the cold worked material, on which the first cold working was performed, at a temperature exceeding the ?? solid solution temperature. It is preferable that the manufacturing method also includes a second cold working step for performing, after the first heat treatment step, a second cold working on the heat-treated material at a working ratio of at least 20%, and a second heat treatment step for heat-treating the second cold worked material, on which the second cold working has been performed, at less than the ?? solvus temperature.Type: ApplicationFiled: February 3, 2016Publication date: January 25, 2018Applicants: HITACHI METALS, LTD., TOHOKU UNIVERSITYInventors: Gang HAN, Koji SATO, Tomonori UENO, Akihiko CHIBA
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Patent number: 9803269Abstract: The present invention provides an ?+? type titanium alloy and a production method therefor, which has an ultrafine structure causing superplasticity under low temperatures and has a high deformation ratio compared to conventional ?+? type Ti alloys. The alloy has an ultrafine structure made of equiaxial crystals in which an area ratio of crystals having a grain diameter of 1 ?m or less is 60% or more, and maximum frequency grain diameter is 0.5 ?m or less, wherein a portion in which the integration degree of plane orientation of the hexagonal close-packed crystal is 1.00 or more exists within a range of 0 to 60 degrees with respect to a normal line of a processed surface of the alloy.Type: GrantFiled: June 28, 2013Date of Patent: October 31, 2017Assignees: NHK SPRING CO., LTD., TOHOKU UNIVERSITYInventors: Hiroaki Matsumoto, Akihiko Chiba, Sang-Hak Lee, Yoshiki Ono
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Publication number: 20170218484Abstract: Provided is a corrosion-resistant, high-hardness alloy composition, which realizes both corrosion resistance and high hardness by using a Ni—Co—Cr—Mo-based alloy and optimizing the chemical composition, heat treatment conditions and processing conditions thereof, and a method for producing that alloy composition. The alloy composition is an alloy composition comprising 15.5% by weight to 16.5% by weight of Cr, 7.5% by weight to 15.5% by weight of Mo, 0% by weight to 30% by weight of Co, 4.5% by weight to 15% by weight of Fe and 0.5% by weight to 4.0% by weight of Cu, with the remainder consisting of Ni and unavoidably included elements, wherein the crystal phase consists only of a ? phase and the Vickers hardness at room temperature is 500 HV or more. The alloy composition is obtained by subjecting an ingot of an alloy having the aforementioned composition to homogenization treatment for 4 hours to 24 hours at 1100° C. to 1300° C.Type: ApplicationFiled: August 5, 2014Publication date: August 3, 2017Applicants: TOHOKU UNIVERSITY, KABUSHIKA KAISHA EIWAInventors: Yunping LI, Akihiko CHIBA
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Patent number: 9624565Abstract: An alloy having an ?? martensite which is a processing starting structure is hot worked. The alloy is heated at a temperature increase rate of 50 to 800° C./sec, and strain is given at not less than 0.5 by a processing strain rate of from 0.01 to 10/sec in a case of a temperature range of 700 to 800° C., or by a processing strain rate of 0.1 to 10/sec in a case of a temperature range of 800° C. to 1000° C. By generating equiaxial crystals having average crystal particle diameters of less than 1000 nm through the above processes, a titanium alloy having high strength and high fatigue resistant property can be obtained, in which hardness is less than 400 HV, tensile strength is not less than 1200 MPa, and static strength and dynamic strength are superior.Type: GrantFiled: November 22, 2011Date of Patent: April 18, 2017Assignees: NHK SPRING CO., LTD., TOHOKU UNIVERSITYInventors: Sang-Hak Lee, Yoshiki Ono, Hiroaki Matsumoto, Akihiko Chiba
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Publication number: 20160097115Abstract: Provided is a Co—Ni-based alloy in which a crystal is easily controlled, a method of controlling a crystal of a Co—Ni-based alloy, a method of producing a Co—Ni-based alloy, and a Co—Ni-based alloy having controlled crystallinity. The Co—Ni-based alloy includes Co, Ni, Cr, and Mo, in which the Co—Ni-based alloy has a crystal texture in which a Goss orientation is a main orientation. The Co—Ni-based alloy preferably has a composition including, in terms of mass ratio: 28 to 42% of Co, 10 to 27% of Cr, 3 to 12% of Mo, 15 to 40% of Ni, 0.1 to 1% of Ti, 1.5% or less of Mn, 0.1 to 26% of Fe, 0.1% or less of C, and an inevitable impurity; and at least one kind selected from the group consisting of 3% or less of Nb, 5% or less of W, 0.5% or less of Al, 0.1% or less of Zr, and 0.01% or less of B.Type: ApplicationFiled: December 11, 2015Publication date: April 7, 2016Applicants: Seiko Instruments Inc., Tohoku UniversityInventors: Akihiko Chiba, Takuma Otomo, Yasunori Akasaka, Tomoo Kobayashi, Ryo Sugawara
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Patent number: 9260769Abstract: A first object of the present invention is to provide Co-based alloys for biomedical applications which are Ni-free, high intensity and high elastic modulus and are suitable for plastic workability. Moreover, a second object of the present invention is to provide Co-based alloys for biomedical applications having X-ray visibility. Furthermore, a third object of the present invention is to provide a stent using the alloys. The Co-based alloys for biomedical applications according to the present invention is configured by adding alloy elements having biocompatibility and an effect of increasing stacking fault energy of the alloys.Type: GrantFiled: September 19, 2012Date of Patent: February 16, 2016Assignee: SEIKO INSTRUMENTS INC.Inventor: Akihiko Chiba
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Patent number: 9260773Abstract: A titanium alloy has high strength and superior workability and is preferably used for various structural materials for automobiles, etc. The titanium alloy is obtained by the following production method. An alloy having a structure of ?? martensite phase is hot worked at conditions at which dynamic recrystallization occurs. The working is performed at a heating rate of 50 to 800° C./second at a strain rate of 0.01 to 10/second when the temperature is 700 to 800° C. or at a strain rate of 0.1 to 10/second when the temperature is more than 800° C. and less than 1000° C. so as to provide a strain of not less than 0.5. Thus, equiaxed crystals with an average grain size of less than 1000 nm are obtained.Type: GrantFiled: September 22, 2010Date of Patent: February 16, 2016Assignees: NHK SPRING CO., LTD., TOHOKU UNIVERSITYInventors: Sang-Hak Lee, Yoshiki Ono, Kazuya Ikai, Hiroaki Matsumoto, Akihiko Chiba
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Publication number: 20150159252Abstract: The present invention provides an ?+? type titanium alloy and a production method therefor, which has an ultrafine structure causing superplasticity under low temperatures and has a high deformation ratio compared to conventional ?+? type Ti alloys. The alloy has an ultrafine structure made of equiaxial crystals in which an area ratio of crystals having a grain diameter of 1 ?m or less is 60% or more, and maximum frequency grain diameter is 0.5 ?m or less, wherein a portion in which the integration degree of plane orientation of the hexagonal close-packed crystal is 1.00 or more exists within a range of 0 to 60 degrees with respect to a normal line of a processed surface of the alloy.Type: ApplicationFiled: June 28, 2013Publication date: June 11, 2015Applicant: NHK Spring Co., Ltd.Inventors: Hiroaki Matsumoto, Akihiko Chiba, Sang-Hak Lee, Yoshiki Ono
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Publication number: 20130284325Abstract: An alloy having an ?? martensite which is a processing starting structure is hot worked. The alloy is heated at a temperature increase rate of 50 to 800° C./sec, and strain is given at not less than 0.5 by a processing strain rate of from 0.01 to 10/sec in a case of a temperature range of 700 to 800° C., or by a processing strain rate of 0.1 to 10/sec in a case of a temperature range of 800° C. to 1000° C. By generating equiaxial crystals having average crystal particle diameters of less than 1000 nm through the above processes, a titanium alloy having high strength and high fatigue resistant property can be obtained, in which hardness is less than 400 HV, tensile strength is not less than 1200 MPa, and static strength and dynamic strength are superior.Type: ApplicationFiled: November 22, 2011Publication date: October 31, 2013Applicants: TOHOKU UNIVERSITY, NHK SPRING CO., LTD.Inventors: Sang-Hak Lee, Yoshiki Ono, Hiroaki Matsumoto, Akihiko Chiba