Title:
SINTERED MAGNET PRODUCTION METHOD
Document Type and Number:
WIPO Patent Application WO/2014/123079
Kind Code:
A1
Abstract:
The present invention addresses the problem of providing a sintered magnet production method whereby cracks in sintered magnets are unlikely to occur. This method has: a pulverization step in which an alloy ingot of a sintered magnet raw material is pulverized by a method including hydrogen disintegration; a filling step in which the alloy powder obtained by the pulverization step is filled into a cavity; an orientation step in which the alloy powder is magnetically oriented by applying a magnetic field to the alloy powder; and a sintering step in which the alloy powder is sintered by heating same using a prescribed temperature history. In the sintering step, the alloy powder is heated in an inert gas atmosphere having a higher pressure than atmospheric pressure, at a prescribed pressurization maintenance temperature being higher than a hydrogen elimination temperature and no more than the sintering temperature. As a result of this heating under pressure by an inert gas, the rapid elimination of hydrogen gas molecules residual in the alloy power is prevented, and cracks in the sintered magnet are made less likely to occur.
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Inventors:
SAGAWA MASATO (JP)
YOSHIKAWA NORIO (JP)
YOSHIKAWA NORIO (JP)
Application Number:
PCT/JP2014/052413
Publication Date:
August 14, 2014
Filing Date:
February 03, 2014
Export Citation:
Assignee:
INTERMETALLICS CO LTD (JP)
DAIDO STEEL CO LTD (JP)
DAIDO STEEL CO LTD (JP)
International Classes:
H01F41/02; B22F3/00; B22F3/02; B22F3/10; B22F3/24; C22C33/02; C22C38/00; H01F1/057; H01F1/08
Foreign References:
| JP2006274306A | 2006-10-12 | |||
| JP2002246253A | 2002-08-30 | |||
| JP2006019521A | 2006-01-19 |
Other References:
J. M. D. COEY: "Rare-earth Iron Pennanent Magnets", 1996, OXFORD UNIVERSITY PRESS, pages: 353
See also references of EP 2955732A4
See also references of EP 2955732A4
Attorney, Agent or Firm:
Kyoto International Patent Law Office (JP)
Patent business corporation Kyoto international patent firm (JP)
Patent business corporation Kyoto international patent firm (JP)
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