Title:
PROCESS FOR PRODUCING RFeB-BASED SINTERED MAGNET
Document Type and Number:
WIPO Patent Application WO/2016/111346
Kind Code:
A1
Abstract:
This process for producing an RFeB-based sintered magnet comprises: a step S1 in which an RFeB-based alloy billet having a rare-earth-element R content of 26.5-29.5 wt% is subjected to an HDDR treatment in which the billet is heated in a hydrogen atmosphere having a temperature of 700-1,000ºC and thereafter the atmosphere is made vacuum while keeping the temperature at 750-900ºC, thereby producing an HDDR-treated raw alloy billet consisting of a polycrystalline object made up of crystal grains having an average grain diameter of 1 µm or smaller in terms of equivalent circular diameter determined from an electron microscope image; a step S2 in which the HDDR-treated raw alloy billet is heated to a temperature of 700-950ºC while keeping the billet in contact with a contact object comprising a second alloy having a higher rare-earth-element R content than the RFeB-based alloy, thereby producing a raw alloy billet having a high rare-earth content; a step S3 in which the raw alloy billet having a high rare-earth content is pulverized to an average particle diameter of 1 µm or smaller, thereby producing a raw alloy powder; an orientation step S4 in which the raw alloy powder is put into a mold and a magnetic field is applied to the raw alloy powder without performing compression molding; and a sintering step S5 in which the raw alloy powder which has undergone the orientation step is heated to a temperature of 850-1,050ºC.
Inventors:
SAGAWA MASATO (JP)
UNE YASUHIRO (JP)
KUBO HIROKAZU (JP)
SUGIMOTO SATOSHI (JP)
MATSUURA MASASHI (JP)
NAKAMURA MICHIHIDE (JP)
UNE YASUHIRO (JP)
KUBO HIROKAZU (JP)
SUGIMOTO SATOSHI (JP)
MATSUURA MASASHI (JP)
NAKAMURA MICHIHIDE (JP)
Application Number:
PCT/JP2016/050443
Publication Date:
July 14, 2016
Filing Date:
January 08, 2016
Export Citation:
Assignee:
INTERMETALLICS CO LTD (JP)
International Classes:
H01F41/02; H01F1/057
Domestic Patent References:
| WO2011004894A1 | 2011-01-13 |
Foreign References:
| JP2014099594A | 2014-05-29 |
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)
Download PDF: