Invention Grant
- Patent Title: R-T-B based sintered magnet
- Patent Title (中): R-T-B系烧结磁体
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Application No.: US14254220Application Date: 2014-04-16
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Publication No.: US09520216B2Publication Date: 2016-12-13
- Inventor: Yasushi Enokido , Kyung-Ku Choi , Ryuji Hashimoto , Daisuke Tanaka
- Applicant: TDK CORPORATION
- Applicant Address: JP Tokyo
- Assignee: TDK CORPORATION
- Current Assignee: TDK CORPORATION
- Current Assignee Address: JP Tokyo
- Agency: Oliff PLC
- Priority: JP2013-089520 20130422
- Main IPC: H01F1/057
- IPC: H01F1/057 ; H01F1/053
Abstract:
An R-T-B based magnet as raw material undergoes heating treatment for a long time and main phase grains turn core-shell like. The R-T-B based magnet includes main phase grains having core and shell portions that covers the core. When the mass concentration of R1 and Y in the core portion is set as αR1 and αY respectively and the mass concentration of R1 and Y in the shell portion is set as βR1 and βY respectively, the ratio (B/A) between the mass concentration ratio of R1 to Y in the shell portion (βR1/βY=B) and the mass concentration ratio of R1 to Y in the core portion (αR1/αY=A) is 1.1 or more. Thus, the decrease of coercivity caused by Y addition is prevented, and the increase effect of temperature characteristics caused by addition of Y will lead to improve the magnetic properties under high temperature.
Public/Granted literature
- US20140311287A1 R-T-B BASED SINTERED MAGNET Public/Granted day:2014-10-23
Information query
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