Oxygen control preparation method and screening device for sintered NdFeB permanent magnet

A screening device and permanent magnet technology, applied in the direction of magnetic objects, inductance/transformer/magnet manufacturing, magnetic materials, etc., can solve problems such as the uniformity of oxygen content in NdFeB magnetic powder, and the difficulty in achieving consistent oxygen content , to achieve the effect of weakening the uneven oxidation reaction, facilitating long-term storage and reducing the degree of corrosion

Active Publication Date: 2021-07-13
宁波源盛磁业有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, it is difficult to achieve the uniformity of the oxygen content of NdFeB magnetic powder by adding oxygen through the jet mill to control the oxygen. Even if the powder is stirred in the later stage, it is difficult to achieve the uniformity of the oxygen content at the microscopic level.

Method used

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  • Oxygen control preparation method and screening device for sintered NdFeB permanent magnet
  • Oxygen control preparation method and screening device for sintered NdFeB permanent magnet
  • Oxygen control preparation method and screening device for sintered NdFeB permanent magnet

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Experimental program
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Effect test

Embodiment 1

[0024] (1) Ingredients: The mass percentage of raw materials is: PrNd: 29%, Ho: 4%, B: 0.94%, Al: 0.9%, Cu: 0.2%, Co: 0.2%, Ga: 0.1%, Zr: 0.1% , the balance is Fe;

[0025] (2) Melting: first put the raw materials into the crucible of the quick-setting furnace for melting, then evacuate the quick-setting furnace to below 1Pa, and start to bake the material. The power of the baking material is set to 100KW, and the material is baked for 20 minutes. , fill with argon to -0.065Mpa, then increase the power to 500KW, start smelting for 10 minutes, adjust the smelting power to 360KW, and carry out refining. The refining time is 5 minutes; when the alloy liquid surface turns silvery white, start casting. piece;

[0026] (3) Hydrogen crushing: put the cast piece into a hydrogen crushing furnace to absorb hydrogen to saturation, then heat to 600°C to dehydrogenate below 20Pa to obtain coarse powder;

[0027] (4) Preparation of fine powder: add 0.1% antioxidant to the coarse powder, f...

Embodiment 2

[0033] (1) Ingredients: The mass percentage of raw materials is: PrNd: 29%, Ho: 4%, B: 0.94%, Al: 0.9%, Cu: 0.2%, Co: 0.2%, Ga: 0.1%, Zr: 0.1% , the balance is Fe;

[0034] (2) Melting: first put the raw materials into the crucible of the quick-setting furnace for melting, then evacuate the quick-setting furnace to below 1Pa, and start to bake the material. The power of the baking material is set to 100KW, and the material is baked for 20 minutes. , fill with argon to -0.065Mpa, then increase the power to 500KW, start smelting for 10 minutes, adjust the smelting power to 360KW, and carry out refining. The refining time is 5 minutes; when the alloy liquid surface turns silvery white, start casting. piece;

[0035] (3) Hydrogen crushing: put the cast piece into a hydrogen crushing furnace to absorb hydrogen to saturation, then heat to 600°C to dehydrogenate below 20Pa to obtain coarse powder;

[0036] (4) Preparation of fine powder: add 0.1% antioxidant to the coarse powder, f...

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Abstract

The invention relates to an oxygen control preparation method and a screening device of a sintered NdFeB permanent magnet, belonging to the field of rare earth permanent magnet materials. The present invention obtains coarse powder through batching, smelting, and hydrogen crushing, and then adds antioxidants to the coarse powder for jet milling treatment. Before jet milling treatment, oxygen is exhausted first, and the coarse powder is ground into fine powder without supplementing oxygen. Add lubricant to the fine powder, use oxygen control screening device to carry out oxygen supplement sieving, and then go through sealing box molding, isostatic pressing, sintering and tempering to obtain NdFeB permanent magnet, so that the permanent magnet after oxygen supplement sieving The material not only obtains a uniform oxidation reaction to achieve the purpose of uniform oxygen control on the sintered NdFeB powder, but also reduces the degree of corrosion, which is beneficial to the long-term preservation of the NdFeB permanent magnet material.

Description

[0001] field of invention [0002] The invention relates to an oxygen control preparation method and a screening device of a sintered NdFeB permanent magnet, belonging to the field of rare earth permanent magnet materials. Background technique [0003] Neodymium iron boron (NdFeB) is currently the most magnetic rare earth permanent magnet material, it has a high magnetic energy product (8MGOe-64MGOe), good coercive force (Hcj) and high temperature resistance. Products are widely used in electric vehicles, wind power generation, inverter air conditioners, nuclear magnetic resonance, CD drives, instruments, mineral processing, toys and other fields. In the process of manufacturing sintered NdFeB permanent magnet materials, oxygen inevitably enters sintered NdFeB magnets from the atmosphere. Although ultra-high-purity raw materials are used, it is impossible to produce pure ternary sintered NdFeB permanent magnets. , is actually a quaternary Nd-Fe-B-O permanent magnet, and oxyge...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01F1/057H01F41/02B22F9/04B22F1/00
CPCH01F1/0577H01F41/0266H01F41/0253B22F9/04B22F2009/044B22F1/145
Inventor 凌聪褚留顺江燕进
Owner 宁波源盛磁业有限公司
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