R-T-B SINTERED MAGNET - HITACHI METALS LTD

Title:

R-T-B SINTERED MAGNET

Document Type and Number:

WIPO Patent Application WO/2012/099188

Kind Code:

A1

Abstract:

This R-T-B rare earth sintered magnet is an R-Fe-B rare earth sintered magnet which has as the main phase R2Fe14B-based compound crystal particles containing a light rare earth element RL (including at least one of Nd and Pr) as the main rare earth element R, and which contains a heavy rare metal element RH (including at least one of Dy and Tb). Prior to removal of the surface layer, this R-T-B rare earth sintered magnet has no layer rich in rare-earth element R on the surface layer, has a site where the coercivity gradually decreases from the surface layer towards the center of the R-T-B rare earth sintered magnet, and the difference between the TRE amount from the surface layer up to 500μm towards the center of the R-T-B rare earth sintered magnet and the TRE amount in the center of the R-T-B rare earth sintered magnet is 0.1-1.0.

Inventors:

KUNIYOSHI FUTOSHI (JP)

Application Number:

PCT/JP2012/051038

Publication Date:

July 26, 2012

Filing Date:

January 19, 2012

Export Citation:

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Assignee:

HITACHI METALS LTD (JP)
KUNIYOSHI FUTOSHI (JP)

International Classes:

H01F1/053; B22F3/24; C22C38/00; H01F1/08

Domestic Patent References:

WO2010109760A1	2010-09-30
WO2011004894A1	2011-01-13
WO2009107397A1	2009-09-03
WO2011007758A1	2011-01-20
WO2012008426A1	2012-01-19
WO2007102391A1	2007-09-13

Foreign References:

JP2004296973A	2004-10-21
JP2009289994A	2009-12-10

Other References: