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Preparation method for low dysprosium heat-resistant sintered neodymium-iron-boron

A NdFeB, heat-resistant technology, applied in the direction of inductance/transformer/magnet manufacturing, magnetic objects, magnetic materials, etc., can solve the problem that the content of Dy element is difficult to control accurately, so as to reduce the temperature, increase the coercive force, and reduce the Dy The effect of element content

Active Publication Date: 2013-09-04
NANJING UNIV OF SCI & TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method relies on special magnetron sputtering technology equipment, and the content of Dy element is difficult to control precisely

Method used

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  • Preparation method for low dysprosium heat-resistant sintered neodymium-iron-boron

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] A method for preparing low-dysprosium heat-resistant sintered NdFeB, comprising the following steps:

[0033] Step 1. Prepare the main alloy, the atomic percentage is: Nd: 14.5%, Fe: 77.0%, B: 6.8%, Co: 0.5%, Al: 1.0%, Nb: 0.2%; it is prepared by vacuum induction quick-setting casting technology The main alloy quick-setting cast sheet. Screen quick-setting cast sheets with a thickness ranging from 0.3 to 0.6 mm, and the volume ratio of columnar crystals is 90%.

[0034] Step 2, preparing auxiliary alloy, the atomic percentage is Dy 60 co 25 al 15 .

[0035]Step 3, using vacuum induction quenching technology to prepare auxiliary alloy quick-setting thin strips, the average thickness of the thin strips is 0.06mm, 600 o C. Perform isothermal crystallization heat treatment on the thin strip for 10 minutes.

[0036] Step 4. Hydrogen crushing of the main alloy quick-setting cast sheet and the auxiliary alloy quick-setting thin strips respectively, and dehydrogenation tr...

Embodiment 2

[0042] A method for preparing low-dysprosium heat-resistant sintered NdFeB, comprising the following steps:

[0043] Step 1, prepare the main alloy, the atomic percentage is: Nd: 10.5%, Pr: 4.0%, Fe: 77.0%, B: 6.8%, Co: 0.5%, Al: 1.0%, Nb: 0.2%; use the vacuum induction speed The quick-setting cast sheet of the main alloy was prepared by solidification casting technology. Screen the quick-setting cast sheets with a thickness range of 0.2-0.4mm, and the volume ratio of columnar crystals is 95%.

[0044] Step 2, preparing auxiliary alloy, the atomic percentage is Dy 63 co 20 al 15 Ga 2 .

[0045] Step 3, preparing auxiliary alloy powder by gas atomization method, the average particle size of the powder is 0.1 μm.

[0046] Step 4. Hydrogen crushing of the quick-setting cast sheet of the main alloy, and dehydrogenation treatment at 500° C. for 4 hours.

[0047] Step 5. Mix the main and auxiliary alloy powders, add gasoline, special antioxidant and lubricant to the powder, a...

Embodiment 3

[0052] A method for preparing low-dysprosium heat-resistant sintered NdFeB, comprising the following steps:

[0053] Step 1. Prepare the main alloy, the atomic percentage is: Nd: 14.0%, Fe: 77.5%, B: 6.1%, Al: 2.0%, Cu: 0.2%, Nb: 0.2%; it is prepared by vacuum induction quick-setting casting technology The main alloy quick-setting cast sheet. The rapid-setting cast sheet with a thickness range of 0.3-0.5mm is screened, and the volume ratio of columnar crystals is 93%.

[0054] Step 2, preparation auxiliary alloy, its atomic percentage is Dy 55 co 25 al 15 Ga 2 Nb 3 .

[0055] Step 3, using the vacuum induction quenching technology to prepare the auxiliary alloy quick-setting thin strip, the average thickness of the thin strip is 0.025mm, 450 o C conduct isothermal crystallization heat treatment on the strip for 1h.

[0056] Step 4. The main alloy quick-setting cast sheet and the auxiliary alloy quick-setting thin strips are respectively subjected to hydrogen crushing, ...

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Abstract

The invention discloses a preparation method for low dysprosium heat-resistant sintered neodymium-iron-boron. The preparation method is characterized in that grain boundary introduction of Dy element is achieved by using a Dy-Co-Al alloy as an auxiliary alloy in a dual alloy-based process; main alloy casting pieces are selected according to the proportion and the thickness of columnar crystals; the average size of jet mill powder is refined; sintering and tempering temperatures are reduced; and the grain growth of the crystal and the diffusion of the Dy element are inhibited, thereby achieving an effect of reducing the Dy element content under the premise of keeping excellent magnetic properties. The method can be widely applied in the preparation and production of high-performance heat-resistant sintered neodymium-iron-boron.

Description

technical field [0001] The invention relates to a method for preparing magnetic materials, in particular to a method for preparing low-dysprosium heat-resistant sintered NdFeB. Background technique [0002] Sintered NdFeB has the highest room temperature magnetic energy product and coercive force, and has been widely used in the fields of electronics and electrical engineering. It is currently the most important permanent magnet material. However, sintered NdFeB generally has a high temperature coefficient, which means that its excellent room temperature magnetic properties have a greater attenuation as the temperature increases. Therefore, the maximum operating temperature is lower. [0003] In order to meet the operating temperature requirements of motors, generators and other application fields, it is necessary to increase the maximum operating temperature of sintered NdFeB. The main approaches include increasing the Curie temperature, coercive force, and magnetocrystal...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/00C22C33/02H01F1/057H01F41/02
Inventor 徐锋李伟朱静陈光卢国文陆凤琪
Owner NANJING UNIV OF SCI & TECH