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Sintered magnet and rotating electric machine using same

A technology of sintered magnets and rotating motors, applied in the direction of magnetic objects, circuits, magnetic materials, etc., can solve the problems of no concentration distribution, achieve the effects of reducing usage, increasing energy product, and improving heat resistance

Inactive Publication Date: 2012-01-04
HITACHI LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the coating method of fluoride is not solution treatment, and there is no description about the concentration distribution of carbon, heavy rare earths, and light rare earths in the oxyfluoride formed at the grain boundary triple point.

Method used

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  • Sintered magnet and rotating electric machine using same
  • Sintered magnet and rotating electric machine using same
  • Sintered magnet and rotating electric machine using same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0057] Produced as Nd-Fe-B powder with Nd 2 Fe 14 The magnetic powder having the B structure as the main phase has fluoride formed on the surface of the magnetic powder. For example, in DyF 3 In the case of forming on the surface of magnetic powder, use H 2 O dissolves Dy(CH 3 COO) 3 , and add HF. By adding HF, a gel-like DyF is formed 3 ·xH 2 O or DyF 3 ·x(CH 3 COO) (x is a positive number). After the solvent was removed by centrifugation (after solid-liquid separation), approximately the same amount of methanol was added to remove anions to obtain a translucent treatment solution. The viscosity of the treatment solution is equivalent to that of water.

[0058] Insert the magnetic powder into the mold and use 1t / cm in the magnetic field of 10kOe 2 The load to make the preform. There is a continuous gap (so-called open pore) on the preform. The bottom surface of the preform was immersed in the treatment solution having the above-mentioned translucency. In additi...

Embodiment 2

[0064] Nd-Fe-B powder is based on Nd 2 Fe 14 The B structure is the main phase, and a magnetic powder with an average particle size of 5 μm having about 1% boride and a rare earth-rich phase is produced, and fluoride is formed on the surface of the magnetic powder. For example, in DyF 3 In the case of forming on the surface of magnetic powder, Dy(CH 3 COO) 3 with H 2 O dissolved and HF was added. Gel-like DyF formed by addition of HF 3 ·xH 2 O or DyF 3 ·x(CH 3 COO) (x is a positive number). After this was centrifuged to remove the solvent (after solid-liquid separation), approximately the same amount of methanol was added to remove anions to obtain a light-transmitting treatment solution. The treatment solution has the same viscosity as water.

[0065] Insert the magnetic powder into the mold and in the magnetic field of 5kOe at 0.5t / cm 2 The load to make the preform. The relative density of the preform is about 60%, and there is a continuous gap (so-called open p...

Embodiment 3

[0072] The DyF-based treatment solution was prepared as follows. After dissolving Dy acetate in water, slowly add diluted hydrofluoric acid. The oxyfluoride and the oxyfluorocarbon are mixed in the solution obtained by precipitating the gel-like fluoride. The mixed solution was stirred with an ultrasonic stirrer, solid-liquid separation was performed with a centrifugal separator, and methanol was added to the separated solid phase. After fully stirring the colloidal methanol solution, anions were removed to make it transparent. In addition, anions are removed in the treatment solution until the transmittance under visible light reaches 5% or more.

[0073] The preforms were prepared as follows. For Nd in a magnetic field of 10koe 2 Fe 14 B magnetic powder applied 5t / cm 2 A preform with a thickness of 20 mm and a relative density of 70% was produced. Since the preform does not reach a relative density of 100% (much less than 100%) in this way, there must be continuous ga...

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Abstract

A sintered magnet according to the present invention is a sintered magnet configured from a magnetic powder grain having Nd2Fe14B as a main component, in which: fluorine, a heavy rare earth element, oxygen, and carbon are segregated in part of grain-boundary regions of said sintered magnetic powder grain; concentration of the carbon is higher than concentration of the fluorine at a grain-boundary triple junction of the grain-boundary region; and concentration of the heavy rare earth element decreases from said grain-boundary triple junction toward an inside of said magnetic powder grain.

Description

technical field [0001] The present invention relates to a rare earth magnet and a rotating electrical machine using the sintered magnet. Background technique [0002] Patent Document 1 (Japanese Patent Application Laid-Open No. 2003-282312) discloses a rare earth sintered magnet, which contains alloy powder for sintered magnets and fluoride powder by dry mixing or wet mixing, orientation in a magnetic field, powder compaction, and sintering. And the prepared fluoride or oxyfluoride. However, since it is based on the mixing of various powders, the alloy powder for sintered magnets and the fluoride powder tend to be in point contact instead of surface contact, and a large amount of fluorine is required to efficiently form a reaction phase (a fluorine-containing phase). Compound powder and heat treatment at high temperature for a long time. In addition, it is also difficult to form a uniform reaction phase along the surface of the magnetized iron powder. [0003] In addition...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F1/053B22F3/10H01F1/08H01F41/02H02K15/03
CPCC22C2202/02H01F1/0572H01F41/0293H01F1/0577H01F41/0266
Inventor 小室又洋佐通祐一铃木启幸今川尊雄
Owner HITACHI LTD
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