Patents by Inventor Tadao Nomura
Tadao Nomura 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: 20230343496Abstract: An anisotropic rare earth sintered magnet represented by the formula (R1-aZra)x(Fe1-bCOb)100-x-y(M11-cM2c)y. R is Sm and at least one element selected from rare earth elements, M1 is at least one element selected from the group consisting of V, Cr, Mn, Ni, Cu, Zn, Ga, Al, and Si, M2 is at least one element selected from the group consisting of Ti, Nb, Mo, Hf, Ta, and W, and x, y, a, b, and c each satisfy 7?x?15 at %, 4?y?20 at %, 0?a?0.2, 0?b?0.5, and 0?c?0.9. The magnet includes 80% by volume or more of a main phase composed of a compound of a ThMn12 type crystal, the main phase having an average crystal grain size of 1 ?m or more, and an intergranular grain boundary phase being formed between adjacent main phase grains.Type: ApplicationFiled: March 18, 2021Publication date: October 26, 2023Applicant: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Tadao NOMURA, Kazuki OTSUKA, Masayuki KAMATA
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Patent number: 11791093Abstract: A sintered magnet body (RaT1bMcBd) coated with a powder mixture of an intermetallic compound (R1iM1j, R1xT2yM1z, R1iM1jHk), alloy (M1dM2e) or metal (M1) powder and a rare earth (R2) oxide is diffusion treated. The R2 oxide is partially reduced during the diffusion treatment, so a significant amount of R2 can be introduced near interfaces of primary phase grains within the magnet through the passages in the form of grain boundaries. The coercive force is increased while minimizing a decline of remanence.Type: GrantFiled: February 26, 2020Date of Patent: October 17, 2023Assignee: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Hiroaki Nagata, Tadao Nomura, Takehisa Minowa
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Publication number: 20230144451Abstract: An anisotropic rare earth sintered magnet represented by the formula (R1-aZra)x(Fe1-b COb)100-x-y(M11-cM2c)y where R is at least one element selected from rare earth elements and Sm is essential; M1 is at least one of V, Cr, Mn, Ni, Cu, Zn, Ga, Al, and Si; M2 is at least one of Ti, Nb, Mo, Hf, Ta, and W; and x, y, a, b, and c each satisfy certain conditions. The anisotropic rare earth sintered magnet includes 80% by volume or more of a main phase composed of a compound of a ThMn12 type crystal, the main phase having an average crystal grain size of 1 ?m or more, and containing an R-rich phase and an R(Fe,Co)2 phase in a grain boundary portion. A method for producing the anisotropic rare earth sintered magnet is also described.Type: ApplicationFiled: March 18, 2021Publication date: May 11, 2023Applicant: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Tadao NOMURA, Kazuki OTSUKA, Masayuki KAMATA
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Publication number: 20230148121Abstract: The invention provides an anisotropic rare earth sintered magnet having an Nd2Fe14B-type compound crystal as a main phase and containing Ce, and exhibiting good magnetic characteristics, and a method for producing the same. The anisotropic rare earth sintered magnet has a composition of a formula Rx(Fe1?aCoa)100?x?y?zByMz (where R is two or more kinds of elements selected from rare earth elements and indispensably including Nd and Ce), in which the main phase is formed of an Nd2Fe14B-type compound crystal, main phase grains such that the Ce/R? ratio in the center part of the grains (where R? is one or more kinds of elements selected from rare earth elements and indispensably including Nd) is lower than the Ce/R? ratio in the outer shell part thereof exist, and a Ce-containing R?-rich phase and a Ce-containing R?(Fe,Co)2 phase exist in the grain boundary part. The production method is for producing the anisotropic rare earth sintered magnet.Type: ApplicationFiled: October 28, 2022Publication date: May 11, 2023Applicant: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Tadao NOMURA, Masayuki KAMATA
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Publication number: 20220367092Abstract: Provided are an anisotropic rare earth sintered magnet having a ThMn12-type crystal compound as a main phase and exhibits good magnetic characteristics, and a method for producing it. The anisotropic rare earth sintered magnet has a composition of a formula (R1-aZra)v(Fe1-bCob)100-v-w-x-y(M11-cM2c)wOxCy (where R is one or more kinds selected from rare earth elements and indispensably includes Sm, M1 is one or more kinds of elements selected from the group consisting of V, Cr, Mn, Ni, Cu, Zn, Ga, Al, and Si, M2 is one or more kinds of elements selected from the group consisting of Ti, Nb, Mo, Hf, Ta, and W, and v, w, x, y, a, b, and c each satisfy 7?v?15 at %, 4?w?20 at %, 0.2?x?4 at %, 0.2?y?2 at %, 0?a?0.2, 0?b?0.5, and 0?c?0.9), which contains a main phase of a ThMn12-type crystal compound in an amount of 80% by volume or more with the average crystal particle diameter of the main phase being 1 ?m or more, which contains an R oxycarbide in the grain boundary area, and which has a density of 7.Type: ApplicationFiled: April 29, 2022Publication date: November 17, 2022Applicant: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Tadao NOMURA, Kazuki OTSUKA, Masayuki KAMATA
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Patent number: 11482377Abstract: A sintered magnet body (RaT1bMcBd) coated with a powder mixture of an intermetallic compound (R1iM1j, R1xT2yM1z, R1iM1jHk), alloy (M1dM2e) or metal (M1) powder and a rare earth (R2) oxide is diffusion treated. The R2 oxide is partially reduced during the diffusion treatment, so a significant amount of R2 can be introduced near interfaces of primary phase grains within the magnet through the passages in the form of grain boundaries. The coercive force is increased while minimizing a decline of remanence.Type: GrantFiled: February 26, 2020Date of Patent: October 25, 2022Assignee: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Hiroaki Nagata, Tadao Nomura, Takehisa Minowa
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Publication number: 20200203069Abstract: A sintered magnet body (RaT1bMcBd) coated with a powder mixture of an intermetallic compound (R1iM1j, R1xT2yM1z, R1iM1jHk), alloy (M1dM2e) or metal (M1) powder and a rare earth (R2) oxide is diffusion treated. The R2 oxide is partially reduced during the diffusion treatment, so a significant amount of R2 can be introduced near interfaces of primary phase grains within the magnet through the passages in the form of grain boundaries. The coercive force is increased while minimizing a decline of remanence.Type: ApplicationFiled: February 26, 2020Publication date: June 25, 2020Applicant: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Hiroaki Nagata, Tadao Nomura, Takehisa Minowa
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Publication number: 20200194171Abstract: A sintered magnet body (RaT1bMcBd) coated with a powder mixture of an intermetallic compound (R1iM1j, R1xT2yM1z, R1iM1jHk), alloy (M1dM2e) or metal (M1) powder and a rare earth (R2) oxide is diffusion treated. The R2 oxide is partially reduced during the diffusion treatment, so a significant amount of R2 can be introduced near interfaces of primary phase grains within the magnet through the passages in the form of grain boundaries. The coercive force is increased while minimizing a decline of remanence.Type: ApplicationFiled: February 26, 2020Publication date: June 18, 2020Applicant: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Hiroaki Nagata, Tadao Nomura, Takehisa Minowa
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Publication number: 20200194170Abstract: A sintered magnet body (RaT1bMcBd) coated with a powder mixture of an intermetallic compound (R1iM1j, R1xT2yM1z, R1iM1jHk), alloy (M1dM2e) or metal (M1) powder and a rare earth (R2) oxide is diffusion treated. The R2 oxide is partially reduced during the diffusion treatment, so a significant amount of R2 can be introduced near interfaces of primary phase grains within the magnet through the passages in the form of grain boundaries. The coercive force is increased while minimizing a decline of remanence.Type: ApplicationFiled: February 26, 2020Publication date: June 18, 2020Applicant: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Hiroaki Nagata, Tadao Nomura, Takehisa Minowa
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Patent number: 10614952Abstract: A sintered magnet body (RaT1bMcBd) coated with a powder mixture of an intermetallic compound (R1iM1j, R1xT2yM1z, R1iM1jHk), alloy (M1dM2e) or metal (M1) powder and a rare earth (R2) oxide is diffusion treated. The R2 oxide is partially reduced during the diffusion treatment, so a significant amount of R2 can be introduced near interfaces of primary phase grains within the magnet through the passages in the form of grain boundaries. The coercive force is increased while minimizing a decline of remanence.Type: GrantFiled: March 9, 2017Date of Patent: April 7, 2020Assignee: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Hiroaki Nagata, Tadao Nomura, Takehisa Minowa
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Patent number: 10167573Abstract: A method of producing a SiC single crystal includes: disposing a SiC seed crystal at a bottom part inside a graphite crucible; causing a solution containing Si, C and R (R is at least one selected from the rare earth elements inclusive of Sc and Y) or X (X is at least one selected from the group consisting of Al, Ge, Sn, and transition metals exclusive of Sc and Y) to be present in the crucible; supercooling the solution so as to cause the SiC single crystal to grow on the seed crystal; and adding powdery or granular Si and/or SiC raw material to the solution from above the graphite crucible while keeping the growth of the SiC single crystal.Type: GrantFiled: November 21, 2011Date of Patent: January 1, 2019Assignee: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Tadao Nomura, Norio Yamagata, Takehisa Minowa
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Patent number: 10160037Abstract: A rare earth magnet is prepared by disposing a R1-T-B sintered body comprising a R12T14B compound as a major phase in contact with an R2-M alloy powder and effecting heat treatment for causing R2 element to diffuse into the sintered body. The alloy powder is obtained by quenching a melt containing R2 and M. R1 and R2 are rare earth elements, T is Fe and/or Co, M is selected from B, C, P, Al, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, In, Sn, Sb, Hf, Ta, W, Pt, Au, Pb, and Bi.Type: GrantFiled: August 18, 2014Date of Patent: December 25, 2018Assignee: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Tadao Nomura, Hiroaki Nagata, Takehisa Minowa
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Patent number: 10074477Abstract: A rare earth sintered magnet is an anisotropic sintered body comprising Nd2Fe14 B crystal phase as primary phase and having the composition R1aTbMcSidBe wherein R1 is a rare earth element inclusive of Sc and Y, T is Fe and/or Co, M is Al, Cu, Zn, In, P, S, Ti, V, Cr, Mn, Ni, Ga, Ge, Zr, Nb, Mo, Pd, Ag, Cd, Sn, Sb, Hf, Ta, or W, “a” to “e” are 12?a?17, 0?c?10, 0.3?d?7, 5?e?10, and the balance of b, wherein Dy and/or Tb is diffused into the sintered body from its surface.Type: GrantFiled: December 12, 2016Date of Patent: September 11, 2018Assignee: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Hiroaki Nagata, Yuuji Gouki, Kazuaki Sakaki, Tadao Nomura, Koichi Hirota, Hajime Nakamura
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Publication number: 20170186534Abstract: A sintered magnet body (RaT1bMcBd) coated with a powder mixture of an intermetallic compound (R1iM1j, R1xT2yM1z, R1iM1jHk), alloy (M1dM2e) or metal (M1) powder and a rare earth (R2) oxide is diffusion treated. The R2 oxide is partially reduced during the diffusion treatment, so a significant amount of R2 can be introduced near interfaces of primary phase grains within the magnet through the passages in the form of grain boundaries. The coercive force is increased while minimizing a decline of remanence.Type: ApplicationFiled: March 9, 2017Publication date: June 29, 2017Applicant: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Hiroaki Nagata, Tadao Nomura, Takehisa Minowa
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Publication number: 20170098503Abstract: A rare earth sintered magnet is an anisotropic sintered body comprising Nd2Fe14 B crystal phase as primary phase and having the composition R1aTbMcSidBe wherein R1 is a rare earth element inclusive of Sc and Y, T is Fe and/or Co, M is Al, Cu, Zn, In, P, S, Ti, V, Cr, Mn, Ni, Ga, Ge, Zr, Nb, Mo, Pd, Ag, Cd, Sn, Sb, Hf, Ta, or W, “a” to “e” are 12?a?17, 0?c?10, 0.3?d?7, 5?e?10, and the balance of b, wherein Dy and/or Tb is diffused into the sintered body from its surface.Type: ApplicationFiled: December 12, 2016Publication date: April 6, 2017Applicant: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Hiroaki Nagata, Yuuji Gouki, Kazuaki Sakaki, Tadao Nomura, Koichi Hirota, Hajime Nakamura
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Patent number: 9044810Abstract: A rare earth magnet is prepared by disposing a R1-T-B sintered body comprising a R12T14B compound as a major phase in contact with an R2-M alloy powder and effecting heat treatment for causing R2 element to diffuse into the sintered body. The alloy powder is obtained by quenching a melt containing R2 and M. R1 and R2 are rare earth elements, T is Fe and/or Co, M is selected from B, C, P, Al, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, In, Sn, Sb, Hf, Ta, W, Pt, Au, Pb, and Bi.Type: GrantFiled: June 29, 2010Date of Patent: June 2, 2015Assignee: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Tadao Nomura, Hiroaki Nagata, Takehisa Minowa
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Publication number: 20150093501Abstract: A rare earth magnet is prepared by disposing a R1-T-B sintered body comprising a R12T14B compound as a major phase in contact with an R2-M alloy powder and effecting heat treatment for causing R2 element to diffuse into the sintered body. The alloy powder is obtained by quenching a melt containing R2 and M. R1 and R2 are rare earth elements, T is Fe and/or Co, M is selected from B, C, P, Al, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, In, Sn, Sb, Hf, Ta, W, Pt, Au, Pb, and Bi.Type: ApplicationFiled: August 18, 2014Publication date: April 2, 2015Applicant: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Tadao Nomura, Hiroaki Nagata, Takehisa Minowa
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Publication number: 20130271248Abstract: A rare earth sintered magnet as an anisotropic sintered body comprising Nd2Fe14B crystal phase as primary phase and having the composition R1aTbMcSidBe wherein R1 is a rare earth element inclusive of Sc and Y, T is Fe and/or Co, H is Al, Cu, Zn, In, P, S, Ti, V, Cr, Mn, Ni, Ga, Ge, Zr, Nb, Mo, Pd, Ag, Cd, Sn, Sb, Hf, Ta, or W, “a” to “e” are 12?a?17, 0?c?10, 0.3?d?7, 5?e?10, and the balance of b, wherein Dy and/or Tb is diffused into the sintered body from its surface.Type: ApplicationFiled: April 11, 2013Publication date: October 17, 2013Applicant: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Hiroaki Nagata, Yuuji Gouki, Kazuaki Sakaki, Tadao Nomura, Koichi Hirota, Hajime Nakamura
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Patent number: 8557057Abstract: A rare earth permanent magnet is prepared by disposing a powdered metal alloy containing at least 70 vol % of an intermetallic compound phase on a sintered body of R—Fe—B system, and heating the sintered body having the powder disposed on its surface below the sintering temperature of the sintered body in vacuum or in an inert gas for diffusion treatment. The advantages include efficient productivity, excellent magnetic performance, a minimal or zero amount of Tb or Dy used, an increased coercive force, and a minimized decline of remanence.Type: GrantFiled: October 27, 2010Date of Patent: October 15, 2013Assignee: Shin-Etsu Chemical Co., Ltd.Inventors: Hiroaki Nagata, Tadao Nomura, Takehisa Minowa
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Publication number: 20120280775Abstract: A sintered magnet body (RaT1bMcBd) coated with a powder mixture of an intermetallic compound R1iM1j, R1xT2yM1z, R1iM1jHk), alloy (M1dM2e)or metal (M1) powder and a rare earth (R2) oxide is diffusion treated. The R2 oxide is partially reduced during the diffusion treatment, so a significant amount of R2 can be introduced near interfaces of primary phase grains within the magnet through the passages in the form of grain boundaries. The coercive force is increased while minimizing a decline of remanence.Type: ApplicationFiled: May 1, 2012Publication date: November 8, 2012Applicant: SHIN-ETSU CHEMICAL CO., LTD.Inventors: Hiroaki Nagata, Tadao Nomura, Takehisa Minowa