Title:
R-T-B-BASED RARE EARTH PERMANENT MAGNET
Document Type and Number:
WIPO Patent Application WO/2019/151245
Kind Code:
A1
Abstract:
An R-T-B-based rare earth permanent magnet in which the composition formula is represented by (R11-x-ySmxR2y)aTbBcMd, wherein: R1 is one or more rare earth elements not including Sm or Y; R2 is one or more rare earth elements from among Y, Ce, and La; T is Fe, etc.; M is Ga, etc.; x and y are in the region indicated in fig. 1; the relationships 0.16 ≤ a/b ≤ 0.28, 0.050 ≤ c/b ≤ 0.075, and 0.005 ≤ d/b ≤ 0.028 are satisfied; the R-T-B-based rare earth permanent magnet includes a grain boundary phase and a main phase comprising an R2T14B compound; the average crystal grain diameter of the main-phase crystal particles is D50 ≤ 4.00 μm; the granularity distribution is (D90-D10)/D50 ≤ 1.60; and the coverage of the grain boundary phase is at least 70.0%.
Inventors:
TAKEDA KEIJI (JP)
MIYAZAKI SHOTA (JP)
MIYAZAKI SHOTA (JP)
Application Number:
PCT/JP2019/002960
Publication Date:
August 08, 2019
Filing Date:
January 29, 2019
Export Citation:
Assignee:
TDK CORP (JP)
International Classes:
H01F1/057; B22F3/00; C22C38/00
Domestic Patent References:
| WO2016175332A1 | 2016-11-03 |
Foreign References:
| DE102017115769A1 | 2018-01-18 | |||
| DE102017115791A1 | 2018-01-18 |
Attorney, Agent or Firm:
MAEDA & SUZUKI (JP)
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