Title:
METHOD OF PRODUCING RARE EARTH MAGNET
Document Type and Number:
Japanese Patent JP2014212255
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a method of producing a rare earth magnet, by which a rare earth magnet excellent in magnetic characteristics can be produced.SOLUTION: A hydrogenation material containing hydrogen compound of rare earth element and Fe is subjected to the following dehydrogenation treatment. A temperature of the hydrogenation material is raised to a temperature Tof 870°C or higher in hydrogen atmosphere, and on and after reaching the temperature T, depressurization of atmosphere is started. The depressurization is performed until hydrogen pressure in the atmosphere comes to be a predetermined value P1 which is 101 hPa or less. While depressurizing the hydrogen pressure from the predetermined value P1 down to a predetermined value P2 of 10.1 Pa or less, the temperature is lowered at a predetermined temperature drop rate down to a temperature Twhich is 700°C to less than 850°C. The hydrogenation material is held at the temperature Tin a depressurized atmosphere in which the hydrogen pressure is the predetermined value P2 or less. Assuming that Vp is exhaust speed of hydrogen, VH is saturation storage amount of hydrogen, and α is a constant of 0.97-3.0, temperature drop speed ΔT/Δt satisfies ΔT/Δt=αlog(Vp/(100×VH)). During a period from depressuring start Sto end of temperature holding, the hydrogenation material is applied with a strong magnetic field pf 4T or higher.
Inventors:
MAEDA TORU
NAGASAWA MOTOKI
NAGASAWA MOTOKI
Application Number:
JP2013088549A
Publication Date:
November 13, 2014
Filing Date:
April 19, 2013
Export Citation:
Assignee:
SUMITOMO ELECTRIC INDUSTRIES
International Classes:
H01F41/02; B22F3/00; B22F3/24; C22C33/02; C22C38/00; H01F1/057; H01F1/08
Attorney, Agent or Firm:
Hiroshi Yamano
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