Title:
PERMANENT MAGNET AND PERMANENT MAGNET POWDER
Document Type and Number:
WIPO Patent Application WO/2018/101408
Kind Code:
A1
Abstract:
[Problem] To provide a permanent magnet or the like that has, as the main phase, a compound having an Nd5Fe17-type crystal structure that exhibits a high residual magnetization and coercive force. [Solution] This permanent magnet contains R and T (where: R represents one or more rare-earth elements that essentially include Sm; T represents Fe or one or more transition metal elements that essentially include Fe and Co). In this permanent magnet, the compositional ratio of R is 20-40 at%, and the remaining portion is substantially only T or only T and C. The contained amount of T is more than 1.5-fold but less than 4.0-fold of the contained amount of R. The main phase particles included in the permanent magnet have an Nd5Fe17-type crystal structure. The main phase particles of the permanent magnet have an average crystal grain size greater than 1 μm. The number percentage of the main phase particles having a crystal grain size of less than 0.4 μm is less than 20%.
Inventors:
ITO MASASHI (JP)
NAGAMINE YUKI (JP)
NAGAMINE YUKI (JP)
Application Number:
PCT/JP2017/043073
Publication Date:
June 07, 2018
Filing Date:
November 30, 2017
Export Citation:
Assignee:
TDK CORP (JP)
International Classes:
H01F1/055; B22F1/142; B22F3/00; C22C33/02; C22C38/00; H01F1/058; B22F1/10
Foreign References:
| JP2016178213A | 2016-10-06 | |||
| JP2016134498A | 2016-07-25 |
Other References:
SAITO, TETSUJI ET AL.: "Magnetic properties of Sm5Fe17 melt-spun ribbons and their borides", AIMS MATERIALS SCIENCE, vol. 2, no. 4, 22 October 2015 (2015-10-22), pages 392 - 400, XP055562310
SAITO, TETSUJI ET AL.: "Magnetic properties of (Sm, Y)5Fe17 melt-spun ribbons", JOURNAL OF APPLIED PHYSICS, vol. 109, no. 7, 4 April 2011 (2011-04-04), pages 07A724 - 1-07A724-3, XP012148120
SAITO, TETSUJI ET AL.: "Structures and magnetic properties of Sm5Fe17 melt-spun ribbon", JOURNAL OF APPLIED PHYSICS, vol. 111, no. 7, 29 February 2012 (2012-02-29), pages 07E322 - 1-07E322-3, XP012159377
SAITO, TETSUJI ET AL.: "Magnetic properties of (Sm, Y)5Fe17 melt-spun ribbons", JOURNAL OF APPLIED PHYSICS, vol. 109, no. 7, 4 April 2011 (2011-04-04), pages 07A724 - 1-07A724-3, XP012148120
SAITO, TETSUJI ET AL.: "Structures and magnetic properties of Sm5Fe17 melt-spun ribbon", JOURNAL OF APPLIED PHYSICS, vol. 111, no. 7, 29 February 2012 (2012-02-29), pages 07E322 - 1-07E322-3, XP012159377
Attorney, Agent or Firm:
MAEDA & SUZUKI (JP)
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