Title:
R-T-B BASED SINTERED MAGNET AND PRODUCTION METHOD FOR SAME, AND ROTARY MACHINE
Document Type and Number:
WIPO Patent Application WO/2013/054842
Kind Code:
A1
Abstract:
Provided is an R-T-B based sintered magnet (10) having a composition that includes a rare earth element, a transition element, and boron. The R-T-B based sintered magnet (10) contains substantially no dysprosium as the rare earth element, and comprises crystal grains (12) having a composition that includes a rare earth element, a transition element, and boron; and grain boundary regions formed between the crystal grains (12). Triple point regions (14), which are grain boundary regions bounded by three or more crystal grains (12), have a composition that includes a rare earth element, a transition element, and boron, and in which the rare earth element mass ratio is greater than in the crystal grains (12). The average surface area of the triple point regions (14) in a cross section is 2 µm2 or less, the standard deviation of the surface area distribution being 3 or less.
Inventors:
KATO EIJI (JP)
ISHIZAKA CHIKARA (JP)
TSUBOKURA TAEKO (JP)
ISHIYAMA TAMOTSU (JP)
JINGU NOBUHIRO (JP)
ISHIZAKA CHIKARA (JP)
TSUBOKURA TAEKO (JP)
ISHIYAMA TAMOTSU (JP)
JINGU NOBUHIRO (JP)
Application Number:
PCT/JP2012/076310
Publication Date:
April 18, 2013
Filing Date:
October 11, 2012
Export Citation:
Assignee:
TDK CORP (JP)
International Classes:
H01F1/057; B22D11/00; B22D11/06; B22F3/00; B22F9/04; C22C33/02; C22C38/00; H01F1/08; H01F41/02
Domestic Patent References:
| WO2005095024A1 | 2005-10-13 |
Foreign References:
| JP2008264875A | 2008-11-06 | |||
| JP2006265609A | 2006-10-05 | |||
| JP2006019521A | 2006-01-19 | |||
| JPH09260122A | 1997-10-03 | |||
| JP2011210838A | 2011-10-20 |
Attorney, Agent or Firm:
HASEGAWA Yoshiki et al. (JP)
Yoshiki Hasegawa (JP)
Yoshiki Hasegawa (JP)
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Claims: