公开(公告)号：US20140210582A1

公开(公告)日：2014-07-31

申请号：US14342095

申请日：2012-10-01

Applicant: NITTO DENKO CORPORATION

Inventor： Izumi Ozeki ,  Katsuya Kume ,  Toshiaki Okuno ,  Tomohiro Omure ,  Takashi Ozaki ,  Keisuke Taihaku ,  Takashi Yamamoto

IPC: H01F1/01 ,  H01F41/02

CPC classification number: H01F1/015 ,  B22F3/12 ,  B22F2009/044 ,  B22F2998/10 ,  C22C33/0278 ,  C22C38/002 ,  C22C38/005 ,  C22C2202/02 ,  H01F1/0577 ,  H01F1/086 ,  H01F41/0266 ,  B22F2201/10

Abstract: There are provided a rare-earth permanent magnet based on Nd—Fe—B, capable of improving coercive force through reducing a residual nitrogen concentration after sintering to be 800 ppm or lower, and a manufacturing method of the rare-earth permanent magnet. The rare-earth permanent magnet based on Nd—Fe—B is obtained through milling a magnet material in an atmosphere of a noble gas by dry milling, and thereafter, compacting the milled magnet material into a formed body in an atmosphere of a noble gas. The formed body is then sintered at 800 through 1180 degrees Celsius so as to obtain a permanent magnet 1 whose nitrogen concentration is 800 ppm or lower, or more preferably 300 ppm or lower.

Abstract translation: 提供了能够通过将烧结后的残留氮浓度降低至800ppm以下来提高矫顽力的Nd-Fe-B系稀土类永久磁铁及稀土永磁体的制造方法。 基于Nd-Fe-B的稀土永磁体是通过在惰性气体的气氛中通过干式研磨将磁体材料研磨而获得的，然后在惰性气体的气氛中将研磨的磁体材料压实成形体 。 然后将成形体在800〜1180摄氏度下烧结，得到氮浓度为800ppm以下，更优选为300ppm以下的永磁体1。

公开(公告)号：US10770207B2

公开(公告)日：2020-09-08

申请号：US14233286

申请日：2013-03-08

Applicant: NITTO DENKO CORPORATION

Inventor： Katsuya Kume ,  Toshiaki Okuno ,  Izumi Ozeki ,  Tomohiro Omure ,  Takashi Ozaki ,  Keisuke Taihaku ,  Takashi Yamamoto

IPC: H01F1/053 ,  B22F1/00 ,  H01F1/057 ,  H01F1/08 ,  B22F3/18 ,  B22F7/04 ,  C22C38/00 ,  H01F41/02

Abstract: There are provided a rare-earth permanent magnet and a manufacturing method of a rare-earth permanent magnet capable of preventing deterioration of magnet properties. In the method, magnet material is milled into magnet powder. Next, a mixture 12 is prepared by mixing the magnet powder and a binder, and the mixture 12 is formed into a sheet-like shape to obtain a green sheet 14. Thereafter, magnetic field orientation is performed to the green sheet 14, which is then held for several hours in a non-oxidizing atmosphere at a pressure higher than normal atmospheric pressure, at 200 through 900 degrees Celsius for calcination. Thereafter, the calcined green sheet 14 is sintered at a sintering temperature. Thereby a permanent magnet 1 is manufactured.

公开(公告)号：US10269475B2

公开(公告)日：2019-04-23

申请号：US15118116

申请日：2014-02-12

Applicant: NITTO DENKO CORPORATION

Inventor： Izumi Ozeki ,  Katsuya Kume ,  Toshiaki Okuno ,  Takashi Ozaki ,  Tomohiro Omure ,  Keisuke Taihaku ,  Takashi Yamamoto

IPC: H01F41/02 ,  H01F1/053 ,  C22C38/00 ,  B22F3/10 ,  B22F3/22 ,  B22F5/00 ,  B22F9/04 ,  C22C1/04 ,  H01F1/057 ,  C22C33/02

Abstract: Provided are a rare-earth permanent magnet whose magnet density after sintering is very high and a method for manufacturing a rare-earth permanent magnet. Thus, a magnet raw material is milled into magnet powder, and then, a compound 12 is formed by mixing the magnet powder thus milled with a binder. Next, the compound 12 thus formed is subjected to a hot-melt molding onto a supporting substrate 13 so as to form a green sheet 14 molded to a sheet-like shape. Thereafter, while the green sheet 14 thus molded is softened by heating, magnetic field orientation is carried out by applying a magnetic field to the green sheet 14 thus heated; and further, the green sheet 14 having been subjected to the magnetic field orientation is calcined by a vacuum sintering, which is further followed by a pressure sintering to produce a permanent magnet 1.

公开(公告)号：US20160141100A1

公开(公告)日：2016-05-19

申请号：US15007318

申请日：2016-01-27

Applicant: NITTO DENKO CORPORATION

Inventor： Keisuke TAIHAKU ,  Katsuya Kume ,  Toshiaki Okuno ,  Izumi Ozeki ,  Tomohiro Omure ,  Takashi Ozaki

IPC: H01F41/02 ,  B22F1/02 ,  C22C38/00 ,  B22F5/00 ,  H01F1/053 ,  B22F1/00 ,  B22F3/10

CPC classification number: H01F1/0536 ,  B22F1/0062 ,  B22F1/02 ,  B22F3/02 ,  B22F3/1021 ,  B22F3/16 ,  B22F5/006 ,  B22F2001/0066 ,  B22F2003/248 ,  B22F2201/01 ,  B22F2301/45 ,  B22F2302/45 ,  B22F2998/10 ,  B22F2999/00 ,  C22C38/002 ,  C22C38/005 ,  C22C2202/02 ,  H01F1/06 ,  H01F1/42 ,  H01F41/0266 ,  B22F9/04 ,  B22F3/10

Abstract: There are provided a rare-earth permanent magnet and a manufacturing method thereof capable of preventing deterioration of magnet properties. In the method, magnet material is milled into magnet powder. Next, a mixture is prepared by mixing the magnet powder and a binder made of long-chain hydrocarbon and/or of a polymer or a copolymer consisting of monomers having no oxygen atoms. Next, the mixture is formed into a sheet-like shape so as to obtain a green sheet. After that, the green sheet is held for a predetermined length of time at binder decomposition temperature in a non-oxidizing atmosphere so as to remove the binder by causing depolymerization reaction or the like to the binder, which turns into monomer. The green sheet from which the binder has been removed is sintered by raising temperature up to sintering temperature. Thereby a permanent magnet 1 is obtained.