Cryogenic treatment method of nano permanent magnetic RE crystal material

A cryogenic treatment, rare earth permanent magnet technology, applied in the direction of magnetic materials, magnetic objects, inductance/transformer/magnet manufacturing, etc., to achieve the effect of improving magnetic properties

Inactive Publication Date: 2004-04-07
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to efficiency and quality problems, the mechanical alloying method is only researched and applied in the laboratory

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[0027] The alloy composition is Nd 9 (Fe 0.9 co 0.1 ) 86 B 6 , the arc heating type melt overflow quick quenching process is adopted, the quenching speed is 25m / s, and the obtained quenched alloy is in the vacuum degree -3 Pa, the temperature is 680°C, stay for 5 minutes for crystallization treatment, the magnetic properties of the alloy are Br=9.8kG s , H CJ =6.1kO e , the annealed alloy was then kept at -190°C for 3 hours, and the cooling and heating rates were 50°C / min. The average grain size of the obtained alloy is 30nm, and the magnetic properties are Br=12kG s , H CJ =7.5kO e .

example 2

[0029] The alloy composition is Nd 10 (Fe 0.8 co 0.2 )B 5 The alloy adopts the arc heating type melt overflow rapid quenching process, and the quenching speed is 20m / s. The obtained quenched alloy is kept at -175°C for 18 hours, and the cooling and heating rate is 20°C / min. Vacuum -3 Pa, crystallization treatment at 700°C for 3 minutes. The average grain size of the alloy is 25nm, and the magnetic property is Br=11.5kG s , H CJ =8.8kO e .

example 3

[0031] The alloy composition is Sm 2 Fe 17 , using the induction heating melt flow injection quenching process, the quenching speed is 20m / s, the quenched alloy is broken into powder, and then nitriding treatment is carried out at 520°C under the mixed gas of ammonia and hydrogen at 520°C, and the obtained Sm 2 Fe 17 N 3 Magnetic powder, the magnetic property is Br=10kG s , HCJ =7.5kO e . SM 2 Fe 17 N 3 The magnetic powder is kept at -150°C for 10 hours, and the crystal grain size of the cryogenically treated alloy with a heating rate of 60°C / min is 35nm, and the magnetic property is Br=11.5kG s , H CJ =8.5kO e .

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Abstract

The present invention provides one cryogenic treatment method of nano permanent magnetic RE crystal material. The treated nano permanent magnetic RE crystal alloy series include single-phase R2Fe14B one, Fe3 / R2Fe14B one, R2Fe14B / alpha-Fe one and Sm2Fe17Nx / alpha-Fe one. The preparation process includes smelting alloy; quick melt quenching to obtain non-crystalline and / or nano crystalline quenched alloy; crystallizing treatment of the quenched alloy; cryogenic treatment of alloy at -199~-135 deg.c for 1-20 hr before and / or after crystallizing treatment of the quenched alloy; and temperature raising in the rate of 10-100 deg.c / min. The said process can refine crystal in 10-50 nm and raise magnetic performance obviously.

Description

technical field [0001] The invention belongs to the technical field of preparation of rare earth permanent magnet materials, and in particular provides a cryogenic treatment method for nanocrystalline rare earth permanent magnets. Background technique: [0002] The rare earth permanent magnet Nd-Fe-B (M.Sagawa et al, J.Appl.Phys.55, 1984, 2083) developed in the early 1980s and the Sm-Fe-N permanent magnet in the early 1990s have good magnetic properties. In the early 1990s, soft magnetic Fe with a grain size of nanoscale was also developed. 3 B is the main phase and hard magnetic Nd 2 Fe 14 B is a nanocomposite permanent magnet material with an auxiliary phase, and it is found that it has a remanence enhancement effect, that is, M r / M s >0.5 (R. Coehoorn et al, J. Magn. Magn. Mater, 80, 1989, 10). Then developed a hard magnetic Nd 2 Fe 14 Nanocomposite rare earth permanent magnet alloy with B as the main phase and soft magnetic αFe as the auxiliary phase (A.Manaf....

Claims

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Application Information

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IPC IPC(8): H01F1/053H01F1/057H01F41/02
Inventor 孙光飞陈菊芳强文江
Owner UNIV OF SCI & TECH BEIJING
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