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    4.
    发明专利
    未知

    公开(公告)号：DE69707185T2

    公开(公告)日：2002-06-27

    申请号：DE69707185

    申请日：1997-04-10

    Applicant: SHOWA DENKO KK

    Inventor： SASAKI SHIRO ,  HASEGAWA HIROSHI ,  HIROSE YOICHI

    IPC: C22C1/04 ,  C22C28/00 ,  H01F1/057 ,  B22F9/02 ,  B22F9/00

    Abstract: The magnetic properties of rare earth magnet are improved by means of forming a novel structure of the cast alloy used for the production of a rare earth magnet, which contains from 27 to 34% by weight of at least one rare earth element (R) including yttrium, from 0.7 to 1.4% by weight of boron, and the balance being essentially iron and, occasionally any other transition element, and comprises an R2T14B phase, an R-rich phase and optionally at least one ternary phase except for the R2T14B phase and the R-rich phase. The novel structure is that the average grain size of the R2T14B phases along the short axes of the columnar grains is from 10 to 100 mu m, the R-rich phase is lamellar and partially granular is crystallized on a boundary and inside the R2T14B phase, and, further, the average spacing between the adjacent R-rich phases is from 3 to 15 mu m. The average grain size of the R2T14B phase is from 4.4 to 7.0 times of the average spacing between the adjacent R-rich phase lamellars. The novel structure can be formed by means of feeding alloy melt onto a rotary casting roll, cooling in a temperature range of from melting point to 1000 DEG C at a cooling rate of 300 DEG C per second or more, and further cooling in a temperature range of from 800 to 600 DEG C at a cooling rate of 1 DEG C/second or less.

    7.
    发明专利
    未知

    公开(公告)号：DE69938004T2

    公开(公告)日：2009-01-15

    申请号：DE69938004

    申请日：1999-06-22

    Applicant: SHOWA DENKO KK

    Inventor： HASEGAWA HIROSHI ,  KAWAMURA NOBUHIKO ,  SASAKI SHIRO ,  HIROSE YOICHI

    IPC: C04B35/10 ,  B22D11/06 ,  B22D11/10 ,  B22D13/10 ,  B22D41/02 ,  C04B35/117 ,  C04B35/48 ,  C04B35/488 ,  C04B35/66 ,  C04B35/76 ,  C04B35/80

    Abstract: Rare-earth alloy is cast into a sheet (6) or the like by using a tundish (3, 13). The refractory material of the tundish used for casting does not necessitate preheating for improving the flowability of the melt (2). The refractory material used essentially consists of 70 wt% or more of Al 2 O 3 and 30 wt% or less of SiO 2 , or 70 wt% or more of ZrO 2 and 30 wt% or less of one or more of Y 2 O 3 , Ce 2 O 3 , CaO, MgO, Al 2 O 3 , TiO 2 and SiO 2 . The refractory material has 1g/cm 3 or less of bulk density, has 0.5 kcal/(mh°C) or less of thermal conductivity in the temperature range of from 1200 to 1400°C, and has 0.5 wt% or less of ratio of ignition weight-loss under the heating condition of 1400°C for 1 hour.

    8.
    发明专利
    未知

    公开(公告)号：DE69938004D1

    公开(公告)日：2008-03-06

    申请号：DE69938004

    申请日：1999-06-22

    Applicant: SHOWA DENKO KK

    Inventor： HASEGAWA HIROSHI ,  KAWAMURA NOBUHIKO ,  SASAKI SHIRO ,  HIROSE YOICHI

    IPC: C04B35/10 ,  B22D11/06 ,  B22D11/10 ,  B22D13/10 ,  B22D41/02 ,  C04B35/117 ,  C04B35/48 ,  C04B35/488 ,  C04B35/66 ,  C04B35/76 ,  C04B35/80

    Abstract: Rare-earth alloy is cast into a sheet (6) or the like by using a tundish (3, 13). The refractory material of the tundish used for casting does not necessitate preheating for improving the flowability of the melt (2). The refractory material used essentially consists of 70 wt% or more of Al 2 O 3 and 30 wt% or less of SiO 2 , or 70 wt% or more of ZrO 2 and 30 wt% or less of one or more of Y 2 O 3 , Ce 2 O 3 , CaO, MgO, Al 2 O 3 , TiO 2 and SiO 2 . The refractory material has 1g/cm 3 or less of bulk density, has 0.5 kcal/(mh°C) or less of thermal conductivity in the temperature range of from 1200 to 1400°C, and has 0.5 wt% or less of ratio of ignition weight-loss under the heating condition of 1400°C for 1 hour.

    9.
    发明专利
    未知

    公开(公告)号：DE69707185D1

    公开(公告)日：2001-11-15

    申请号：DE69707185

    申请日：1997-04-10

    Applicant: SHOWA DENKO KK

    Inventor： SASAKI SHIRO ,  HASEGAWA HIROSHI ,  HIROSE YOICHI

    IPC: C22C1/04 ,  C22C28/00 ,  H01F1/057 ,  B22F9/02 ,  B22F9/00

    Abstract: The magnetic properties of rare earth magnet are improved by means of forming a novel structure of the cast alloy used for the production of a rare earth magnet, which contains from 27 to 34% by weight of at least one rare earth element (R) including yttrium, from 0.7 to 1.4% by weight of boron, and the balance being essentially iron and, occasionally any other transition element, and comprises an R2T14B phase, an R-rich phase and optionally at least one ternary phase except for the R2T14B phase and the R-rich phase. The novel structure is that the average grain size of the R2T14B phases along the short axes of the columnar grains is from 10 to 100 mu m, the R-rich phase is lamellar and partially granular is crystallized on a boundary and inside the R2T14B phase, and, further, the average spacing between the adjacent R-rich phases is from 3 to 15 mu m. The average grain size of the R2T14B phase is from 4.4 to 7.0 times of the average spacing between the adjacent R-rich phase lamellars. The novel structure can be formed by means of feeding alloy melt onto a rotary casting roll, cooling in a temperature range of from melting point to 1000 DEG C at a cooling rate of 300 DEG C per second or more, and further cooling in a temperature range of from 800 to 600 DEG C at a cooling rate of 1 DEG C/second or less.

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