Title:
RARE-EARTH SINTERED MAGNET
Document Type and Number:
WIPO Patent Application WO/2013/080605
Kind Code:
A1
Abstract:
[Problem] To provide a rare-earth sintered magnet with improved corrosion resistance. [Solution] This rare-earth sintered magnet is a rare-earth permanent magnet having an R-T-B composition (R is at least one type of element selected from Y and the rare-earth elements, T is at least one type of metal element including Fe or Fe and Co, and B is B or B and C), wherein during an R-rich phase (R is a rare-earth element), which is when the atom ratio at the grain-boundary triple point is (Fe+Co)/(LR+HR+Fe+Co)≤ 0.2 (LR is a light rare-earth element from Y and 57La to 63Eu, and HR is a heavy rare-earth element from 64Gd to 71Lu), a region HR/(LR+HR)≥0.01 (atom ratio) exists in the R-rich phase, the surface-area ratio within the region HR/(LR+HR)≥0.01 accounted for by the grain-boundary triple points being between 10% and 90%.
Inventors:
HAYAKAWA TAKUMA (JP)
KUNIEDA RYOTA (JP)
CHIBA TETSUYA (JP)
NISHIKAWA KEN-ICHI (JP)
KUNIEDA RYOTA (JP)
CHIBA TETSUYA (JP)
NISHIKAWA KEN-ICHI (JP)
Application Number:
PCT/JP2012/069644
Publication Date:
June 06, 2013
Filing Date:
August 02, 2012
Export Citation:
Assignee:
TDK CORP (JP)
HAYAKAWA TAKUMA (JP)
KUNIEDA RYOTA (JP)
CHIBA TETSUYA (JP)
NISHIKAWA KEN-ICHI (JP)
HAYAKAWA TAKUMA (JP)
KUNIEDA RYOTA (JP)
CHIBA TETSUYA (JP)
NISHIKAWA KEN-ICHI (JP)
International Classes:
H01F1/08; B22F3/00; B22F3/02; B22F3/10; B22F3/24; C22C33/02; C22C38/00; H01F1/057
Foreign References:
| JPS6393841A | 1988-04-25 | |||
| JP2011187734A | 2011-09-22 | |||
| JPH09232173A | 1997-09-05 |
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Claims: