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公开(公告)号:US20180294082A1
公开(公告)日:2018-10-11
申请号:US15967893
申请日:2018-05-01
Applicant: TDK CORPORATION
Inventor: Tetsuya HIDAKA , Takuma HAYAKAWA , Makoto IWASAKI , Ayato KAKOKI
IPC: H01F1/057 , H01F41/02 , C22C38/16 , C22C38/14 , C22C38/00 , C22C38/06 , C22C38/04 , C22C38/10 , H01F1/058
Abstract: An R-T-B based sintered magnet includes “R”, “T”, and “B”. “R” represents a rare earth element. “T” represents a metal element other than rare earth elements including at least Fe, Cu, Mn, Al, Co, Ga, and Zr. “B” represents boron or boron and carbon. With respect to 100 mass % of a total mass of the R-T-B based sintered magnet, a content of “R” is 28.0 to 31.5 mass %, a content of Cu is 0.04 to 0.50 mass %, a content of Mn is 0.02 to 0.10 mass %, a content of Al is 0.15 to 0.30 mass %, a content of Co is 0.50 to 3.0 mass %, a content of Ga is 0.08 to 0.30 mass %, a content of Zr is 0.10 to 0.25 mass %, and a content of “B” is 0.85 to 1.0 mass %.
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公开(公告)号:US20170278609A1
公开(公告)日:2017-09-28
申请号:US15439975
申请日:2017-02-23
Applicant: TDK Corporation
Inventor: Jun HAGIWARA , Fumitaka BABA , Makoto IWASAKI , Satoshi KOGA
Abstract: A rare earth magnet capable of reducing an eddy current loss by virtue of a low-cost, simple configuration, when mounted in a motor, is to be provided, where the rare earth magnet comprising: a magnet body comprising a rare earth element and iron; and a resistive layer formed on at least one surface of the magnet body, the resistive layer comprising a rare earth element, iron, and oxygen and having an average volume resistivity of 103 Ωcm or more and a thickness of from 3 to 25 μm, as is shown in FIG. 2.
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公开(公告)号:US20190074114A1
公开(公告)日:2019-03-07
申请号:US16181811
申请日:2018-11-06
Applicant: TDK Corporation
Inventor: Makoto IWASAKI , Tetsuya HIDAKA , Takuma HAYAKAWA , Ayato KAKOKI , Yoshinori FUJIKAWA , Syota GOTO , Haruna NAKAJIMA , Takeshi MASUDA , Chikara ISHIZAKA
Abstract: Provided is a sintered magnet that is an R-T-B based sintered magnet having a region having a concentration of at least one heavy rare earth element decreasing from the surface toward the inside, in which the at least one heavy rare earth element includes at least either of Tb or Dy, R includes Nd, T includes Fe, Co, and Cu, there is a grain boundary phase containing at least either of Tb or Dy and Nd between two main phase particles, and a value obtained by subtracting a half value width of a concentration distribution curve of Cu from a half value width of a concentration distribution curve of Tb or Dy in a part including the grain boundary phase is from 10 to 20 nm.
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14.
公开(公告)号:US20180286544A1
公开(公告)日:2018-10-04
申请号:US15936752
申请日:2018-03-27
Applicant: TDK CORPORATION
Inventor: Takuma HAYAKAWA , Makoto IWASAKI , Tetsuya HIDAKA , Eiji KATO , Hidetake KITAOKA
Abstract: Provided is an alloy for R-T-B based rare earth magnet. “R” is one or more of a rare earth element, ‘T’ is one or more of a transition metal element essentially including Fe or Fe and Co, and “B” is boron. The alloy includes a single or a plural number of main phase (A), having a minimum length of 10 μm or more and a maximum length of 30 μm or more and 300 μm or less, in a cross section cut along a thickness direction of the alloy. The main phase (A) includes an R2T14B phase, and an area ratio of the main phase (A) to an entire cross section is 2% or more and 60% or less.
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公开(公告)号:US20170221616A1
公开(公告)日:2017-08-03
申请号:US15420151
申请日:2017-01-31
Applicant: TDK Corporation
Inventor: Makoto IWASAKI , Tetsuya HIDAKA , Takuma HAYAKAWA , Ayato KAKOKI , Yoshinori FUJIKAWA , Syota GOTO , Haruna NAKAJIMA , Takeshi MASUDA , Chikara ISHIZAKA
IPC: H01F1/055 , C22C38/14 , C22C38/10 , B22F3/10 , C22C38/00 , B22F1/00 , B22F9/02 , C22C38/16 , C22C38/06
CPC classification number: H01F1/0557 , B22F1/0059 , B22F3/1017 , B22F9/026 , B22F2009/044 , B22F2202/05 , B22F2301/35 , B22F2998/10 , B22F2999/00 , C22C33/02 , C22C38/002 , C22C38/005 , C22C38/06 , C22C38/10 , C22C38/14 , C22C38/16 , C22C2202/02 , H01F1/0577 , H01F41/0293 , B22F9/023 , B22F9/04 , B22F3/02 , B22F3/10
Abstract: Provided is a sintered magnet that is an R-T-B based sintered magnet having a region having a concentration of at least one heavy rare earth element decreasing from the surface toward the inside, in which the at least one heavy rare earth element includes at least either of Tb or Dy, R includes Nd, T includes Fe, Co, and Cu, there is a grain boundary phase containing at least either of Tb or Dy and Nd between two main phase particles, and a value obtained by subtracting a half value width of a concentration distribution curve of Cu from a half value width of a concentration distribution curve of Tb or Dy in a part including the grain boundary phase is from 10 to 20 nm.
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公开(公告)号:US20170103835A1
公开(公告)日:2017-04-13
申请号:US15285178
申请日:2016-10-04
Applicant: TDK CORPORATION
Inventor: Tetsuya HIDAKA , Takuma HAYAKAWA , Makoto IWASAKI , Ayato KAKOKI , Naoto TSUKAMOTO , Fumitaka BABA
Abstract: An R-T-B based sintered magnet includes “R”, “T”, and “B”. “R” represents a rare earth element including at least Tb. “T” represents a metal element except rare earth elements including at least Fe, Cu, Mn, Al, and Co. “B” represents boron or boron and carbon. With respect to 100 mass % of a total mass of the R-T-B based sintered magnet, a content of “R” is 28.0 to 32.0 mass %, a content of Cu is 0.04 to 0.50 mass %, a content of Mn is 0.02 to 0.10 mass %, a content of Al is 0.15 to 0.30 mass %, a content of Co is 0.50 to 3.0 mass %, and a content of “B” is 0.85 to 1.0 mass %. Tb2/Tb1 is 0.40 to less than 1.0, where Tb1 and Tb2 (mass %) denote a content of Tb at a surface portion and at a core portion, respectively.
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公开(公告)号:US20180262142A1
公开(公告)日:2018-09-13
申请号:US15607993
申请日:2017-05-30
Applicant: TDK CORPORATION
Inventor: Eiji KATO , Makoto IWASAKI
CPC classification number: H02K41/031 , H02K1/02 , H02K1/16 , H02K1/2766 , H02K2213/03
Abstract: A motor includes a magnet and a coil. α2=[{(Br2−Br1)/Br1}/(T2−T1)]×100≥0.11 and α3=[{(Br3−Br1)/Br1}/(T3−T1)]×100≤0.13 are satisfied. In the magnet, Br1 (mT) is a residual magnetic flux density at T1 (° C.), Br2 (mT) is a residual magnetic flux density at T2 (° C.), and Br3 (mT) is a residual magnetic flux density at T3 (° C.), and α2 (%/° C.) is a temperature coefficient at a target temperature of T2 (° C.) with respect to a reference temperature of T1 (° C.), and α3 (%/° C.) is a temperature coefficient at a target temperature of T3 (° C.) with respect to a reference temperature of T1 (° C.) in conditions of T1=20, T2=100, and T3=220.
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公开(公告)号:US20180025820A1
公开(公告)日:2018-01-25
申请号:US15656284
申请日:2017-07-21
Applicant: TDK Corporation
Inventor: Ayato KAKOKI , Makoto IWASAKI , Tetsuya HIDAKA , Takuma HAYAKAWA
CPC classification number: H01F1/0577 , B22F3/16 , B22F9/04 , B22F2009/044 , B22F2201/11 , B22F2202/05 , B22F2301/45 , B22F2998/10 , B22F2999/00 , C22C28/00 , C22C30/02 , C22C38/002 , C22C38/005 , C22C38/06 , C22C38/10 , C22C38/14 , C22C38/16 , C22C2202/02 , H01F41/0293 , B22F9/023 , B22F1/0059 , B22F3/087 , B22F3/14 , B22F2003/248
Abstract: An R-T-B based sintered magnet containing a first heavy rare earth element, in which R includes Nd, T includes Co and Fe, the first heavy rare earth element includes Tb or Dy, the R-T-B based sintered magnet has a region in which a concentration of the first heavy rare earth element decreases from the surface toward the inside, a first grain boundary phase which contains the first heavy rare earth element and Nd but does not contain Co is present in one cross section including the region, and an area occupied by the first grain boundary phase in one cross section including the region is 1.8% or less.
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公开(公告)号:US20170346432A1
公开(公告)日:2017-11-30
申请号:US15608067
申请日:2017-05-30
Applicant: TDK CORPORATION
Inventor: Makoto IWASAKI , Fumitaka BABA , Chikara ISHIZAKA
Abstract: A motor includes a magnet and a coil. α2=[{(Br2−Br1)/Br1}/(T2−T1)]×100≧−0.10 and α3=[{(Br3−Br1)/Br1}/(T3−T1)]×100≦−0.12 are satisfied. In the magnet, Br1 (mT) is a residual magnetic flux density at T1 (° C.), Br2 (mT) is a residual magnetic flux density at T2 (° C.), and Br3 (mT) is a residual magnetic flux density at T3 (° C.), and α2 (%/° C.) is a temperature coefficient at a target temperature of T2 (° C.) with respect to a reference temperature of T1 (° C.), and α3 (%/° C.) is a temperature coefficient at a target temperature of T3 (° C.) with respect to a reference temperature of T1 (° C.) in conditions of T1=23, T2=60, and T3=180.
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公开(公告)号:US20170103836A1
公开(公告)日:2017-04-13
申请号:US15285113
申请日:2016-10-04
Applicant: TDK CORPORATION
Inventor: Tetsuya HIDAKA , Takuma HAYAKAWA , Makoto IWASAKI , Ayato KAKOKI
CPC classification number: H01F1/0577 , C22C38/002 , C22C38/005 , C22C38/04 , C22C38/06 , C22C38/10 , C22C38/14 , C22C38/16 , H01F1/058 , H01F41/0293
Abstract: An R-T-B based sintered magnet includes “R”, “T”, and “B”. “R” represents a rare earth element. “T” represents a metal element other than rare earth elements including at least Fe, Cu, Mn, Al, Co, Ga, and Zr. “B” represents boron or boron and carbon. With respect to 100 mass % of a total mass of the R-T-B based sintered magnet, a content of “R” is 28.0 to 31.5 mass %, a content of Cu is 0.04 to 0.50 mass %, a content of Mn is 0.02 to 0.10 mass %, a content of Al is 0.15 to 0.30 mass %, a content of Co is 0.50 to 3.0 mass %, a content of Ga is 0.08 to 0.30 mass %, a content of Zr is 0.10 to 0.25 mass %, and a content of “B” is 0.85 to 1.0 mass %.
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