Invention Grant
- Patent Title: R-T-B based sintered magnet and production method for same, and rotary machine
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Application No.: US14351199Application Date: 2012-10-11
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Publication No.: US09613737B2Publication Date: 2017-04-04
- Inventor: Eiji Kato , Chikara Ishizaka , Taeko Tsubokura , Tamotsu Ishiyama , Nobuhiro Jingu
- Applicant: TDK CORPORATION
- Applicant Address: JP Tokyo
- Assignee: TDK CORPORATION
- Current Assignee: TDK CORPORATION
- Current Assignee Address: JP Tokyo
- Agency: Oliff PLC
- Priority: JP2011-226040 20111013; JP2011-226042 20111013; JP2011-248978 20111114; JP2011-248980 20111114
- International Application: PCT/JP2012/076310 WO 20121011
- International Announcement: WO2013/054842 WO 20130418
- Main IPC: C22C33/02
- IPC: C22C33/02 ; C22C38/10 ; B22D11/06 ; H01F1/053 ; H01F1/057 ; H01F1/08 ; H01F41/02 ; C22C38/00 ; C22C38/06 ; C22C38/14 ; C22C38/16

Abstract:
An R-T-B sintered magnet including a composition containing a rare earth element, a transition element and boron, containing essentially no dysprosium as a rare earth element, and having crystal grains with a composition containing a rare earth element, a transition element and boron, and grain boundary regions formed between the crystal grains, wherein the triple point regions which are grain boundary regions surrounded by 3 or more crystal grains have a composition containing a rare earth element, a transition element and boron and have a higher mass ratio of the rare earth element than the crystal grains, the average value of the area of the triple point regions in a cross-section being no greater than 2 μm2 and the standard deviation of the area distribution being no greater than 3.
Public/Granted literature
- US20140286816A1 R-T-B BASED SINTERED MAGNET AND PRODUCTION METHOD FOR SAME, AND ROTARY MACHINE Public/Granted day:2014-09-25
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