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Hydrogen decrepitation process for sintered Nd-Fe-B permanent magnets

A permanent magnet material, NdFeB technology, applied in the direction of magnetic materials, inorganic material magnetism, magnetic objects, etc., can solve the problem of uneven hydrogen absorption of sintered NdFeB cast sheets, and achieve uniform microstructure and intrinsic correction of magnets. The effect of high coercivity and high magnetic properties

Active Publication Date: 2014-01-29
NINGBO YUNSHENG +3
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to provide a hydrogen crushing process for sintered NdFeB cast pieces, which can solve the problem of non-uniform hydrogen absorption of sintered NdFeB cast pieces by activating the cast pieces, thereby improving the uniformity of hydrogen crushed powder, Methods of Improving Magnetic Properties of Sintered NdFeB Magnets

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] (1) Use a vacuum intermediate frequency melting furnace to smelt neodymium (Nd), pure iron (Fe), boron iron (B-Fe), cobalt (Co) and other metals into alloy liquid, and use the quick-setting process to cast the alloy liquid into casting sheet, cast sheet composition is Nd 13 Dy 0.6 Fe 79.2 co 1 B 6 Ga 0.1 Cu 0.1 (atomic percent), in order to suppress grain growth, a certain amount of zirconium (Zr) or niobium (Nb) can also be properly added to the composition.

[0035] (2) Put the cast piece into the hydrogen crushing furnace, heat the temperature to 60 degrees and keep it warm, feed CO gas, the flow rate is 10mL / min, keep the gas feeding time for 30 minutes, then close the CO gas inlet valve, remove the heating, Start vacuuming, and fill with argon for replacement 10 times. Start to pass in hydrogen gas, and the cast piece starts to absorb hydrogen. After the hydrogen absorption is completed, dehydrogenation is carried out.

[0036] (3) Grind the powder in step ...

Embodiment 2

[0042] (1) Use a vacuum intermediate frequency melting furnace to smelt neodymium (Nd), pure iron (Fe), boron iron (B-Fe), cobalt (Co) and other metals into alloy liquid, and use the quick-setting process to cast the alloy liquid into casting sheet, cast sheet composition is Nd 13 Dy 0.6 Fe 79.2 co 1 B 6 Ga 0.1 Cu 0.1 (atomic percent), in order to suppress grain growth, a certain amount of zirconium (Zr) or niobium (Nb) can also be properly added to the composition.

[0043] (2) Put the cast piece into the hydrogen crushing furnace, heat the temperature to 100 degrees and keep it warm, feed CO gas, the flow rate is 50mL / min, keep the gas feeding time for 90 minutes, then close the CO gas inlet valve, remove the heating, Start vacuuming, and fill with argon for replacement 10 times. Start to pass in hydrogen gas, and the cast piece starts to absorb hydrogen. After the hydrogen absorption is completed, dehydrogenation is carried out.

[0044] (3) Grind the powder in step 2...

Embodiment 3

[0050] (1) Use a vacuum intermediate frequency melting furnace to smelt neodymium (Nd), pure iron (Fe), boron iron (B-Fe), cobalt (Co) and other metals into alloy liquid, and use the quick-setting process to cast the alloy liquid into casting sheet, cast sheet composition is Nd 12.4 Dy 1 Fe 79.4 co 1 B 6.5 Ga 0.1 Cu 0.1 (atomic percent), in order to suppress grain growth, a certain amount of zirconium (Zr) or niobium (Nb) can also be properly added to the composition.

[0051] (2) Put the cast piece into the hydrogen crushing furnace, heat the temperature to 150 degrees and keep it warm, feed CO gas, the flow rate is 100mL / min, keep the gas feeding time for 180min, then close the CO gas inlet valve, remove the heating, Start vacuuming, and fill with argon for replacement 10 times. Start to pass in hydrogen gas, and the cast piece starts to absorb hydrogen. After the hydrogen absorption is completed, dehydrogenation is carried out.

[0052] (3) Grind the powder in step ...

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Abstract

The invention relates to a hydrogen decrepitation process for sintered Nd-Fe-B permanent magnets and belongs to the technical field of magnetic materials. The hydrogen decrepitation process includes melting metal materials, quickly solidifying the metal materials into cast pieces, activating the cast pieces under a certain condition, namely heating the cast pieces to 60-150 DEG C, adding a certain amount of CO (carbon monoxide) in flow of 10-100mL / min, then increasing reaction speed of metal slices and hydrogen, and crushing the cast pieces under a certain pressure of hydrogen. The hydrogen decrepitation process comprises a hydrogen decrepitation pretreatment process, and the follow-up process includes regrinding the powder through a micronizer, forming and pressing the fine powder and sintering to manufacture the sintered Nd-Fe-B permanent magnets. The hydrogen decrepitation process has the advantages that sufficiency and uniformity of the sintered Nd-Fe-B cast pieces in hydrogen reaction are improved, size distribution of regrinding of the cast pieces is improved, magnetic performance of the sintered Nd-Fe-B permanent magnets is improved, and performance of the sintered Nd-Fe-B magnets is consequently improved.

Description

technical field [0001] The invention relates to a production method of a rare earth magnet, in particular to a production method of a high-performance sintered NdFeB magnet, specifically a hydrogen crushing process of a sintered NdFeB permanent magnet material, which belongs to the technical field of magnetic materials. technical background [0002] Sintered NdFeB permanent magnet materials have very high magnetic properties. They are used in the field of motors and have a very good energy-saving effect. At the same time, they can reduce the size of the motor. At present, sintered NdFeB permanent magnet materials have become an important supporting basis for energy-saving technology It has become an irreplaceable functional material for micro motors, and has been widely used in home appliances, automobiles, computers, communications, medical, aerospace, military and other fields. Based on its excellent magnetic properties and the needs of modern industrial development, sinte...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22F9/16H01F1/057H01F1/06
Inventor 欧阳习科刘峰
Owner NINGBO YUNSHENG
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