Title:
R-T-B BASED RARE EARTH PERMANENT MAGNET, MOTOR, AUTOMOBILE, POWER GENERATOR AND WIND ENERGY CONVERSION SYSTEM
Document Type and Number:
WIPO Patent Application WO/2012/002060
Kind Code:
A1
Abstract:
Provided is an R-T-B based rare earth permanent magnet wherein a high coercivity (Hcj) can be achieved without increasing the Dy concentration in an R-T-B based alloy and deterioration in magnetization (Br), said deterioration being caused by the addition of Dy, can be inhibited to thereby give excellent magnetic characteristics. The R-T-B based rare earth permanent magnet comprises a sintered body comprising a primary phase, which contains R2Fe14B as the main component, and a grain boundary phase, which contains R in a larger amount than the primary phase, wherein: R represents a rare earth element containing Nd as an essential element; said sintered body contains Ga as an essential element; said grain boundary phase comprises a primary grain boundary phase, a secondary grain boundary phase and a tertiary grain boundary phase, these grain boundary phases being different in total atomic concentration of rare earth elements from each other; and said tertiary grain boundary phase has a lower total atomic concentration of said rare earth elements than the primary and secondary grain boundary phases, and has a higher atomic concentration of Fe than the primary and secondary grain boundary phases.
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Inventors:
NAKAJIMA KENICHIRO (JP)
YAMAZAKI TAKASHI (JP)
YAMAZAKI TAKASHI (JP)
Application Number:
PCT/JP2011/061541
Publication Date:
January 05, 2012
Filing Date:
May 19, 2011
Export Citation:
Assignee:
SHOWA DENKO KK (JP)
NAKAJIMA KENICHIRO (JP)
YAMAZAKI TAKASHI (JP)
NAKAJIMA KENICHIRO (JP)
YAMAZAKI TAKASHI (JP)
International Classes:
H01F1/053; B22F1/00; B22F3/24; B22F9/04; C22C33/02; C22C38/00; H01F1/08; H02K15/03
Domestic Patent References:
| WO2009004794A1 | 2009-01-08 | |||
| WO2010073533A1 | 2010-07-01 |
Foreign References:
| JP2008147634A | 2008-06-26 | |||
| JPS6318603A | 1988-01-26 | |||
| JP2011014631A | 2011-01-20 | |||
| JP3951099B2 | 2007-08-01 | |||
| JP3891307B2 | 2007-03-14 |
Other References:
See also references of EP 2590181A4
Attorney, Agent or Firm:
SHIGA Masatake et al. (JP)
Masatake Shiga (JP)
Masatake Shiga (JP)
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Claims: