Title:
RARE-EARTH SINTERED MAGNET
Document Type and Number:
WIPO Patent Application WO/2018/101409
Kind Code:
A1
Abstract:
[Problem] The purpose of the present invention is to provide a rare-earth sintered magnet having good magnetic properties. [Solution] This rare-earth sintered magnet contains main phase crystal grains having an Nd5Fe17-type crystal structure, comprises R and T (where R represents one or more rare-earth elements that essentially include Sm, and T represents Fe or one or more transition metal elements that essentially include Fe and Co), and is characterized in that: the compositional ratio of R in the rare-earth sintered magnet is 20-40 at% and the remaining portion is substantially T; the remaining portion other than R in the rare-earth sintered magnet is substantially only T or only T and C; and when the average grain size of the main phase crystal grains in one cross-sectional surface of the rare-earth sintered magnet is defined as Dv, while the grain size of individual main phase crystal grains is defined as Di, Dv is at least 1.0 μm, and the area ratio of main phase crystal grains that satisfy 0.7Dv≤Di≤2.0Dv is at least 80% with respect to the area of a cross-sectional surface of the rare-earth sintered magnet.
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Inventors:
IWASA TAKUROU (JP)
HASHIMOTO RYUJI (JP)
ITO MASASHI (JP)
HASHIMOTO RYUJI (JP)
ITO MASASHI (JP)
Application Number:
PCT/JP2017/043075
Publication Date:
June 07, 2018
Filing Date:
November 30, 2017
Export Citation:
Assignee:
TDK CORP (JP)
International Classes:
H01F1/055; C22C33/02; C22C38/00; H01F1/058
Foreign References:
| JP2016178213A | 2016-10-06 | |||
| JP2016134498A | 2016-07-25 |
Other References:
SAITO, TETSUJI ET AL.: "Magnetic properties of Sm5Fel7-based magnets produced by spark plasma sintering method", IOP CONF. SERIES: MATERIALS SCIENCE AND ENGINEERING, vol. 1, no. 1, 10 February 2009 (2009-02-10), pages 012032
SAITO TETSUJI ET AL.: "Magnetic Properties of Sm5Fel7/Fe composite magnets produced by spark plasma sintering method", JOURNAL OF APPLIED PHYSICS, vol. 111, no. 7, 12 March 2012 (2012-03-12), pages 07B534 - 1-07B534-3, XP012159020
SAITO TETSUJI ET AL.: "Magnetic Properties of Sm5Fel7/Fe composite magnets produced by spark plasma sintering method", JOURNAL OF APPLIED PHYSICS, vol. 111, no. 7, 12 March 2012 (2012-03-12), pages 07B534 - 1-07B534-3, XP012159020
Attorney, Agent or Firm:
MAEDA & SUZUKI (JP)
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