Preparation method of neodymium-iron-boron magnet with large-depth grain boundary diffusion

A technology of grain boundary diffusion and NdFeB, applied in the direction of magnetic objects, inductance/transformer/magnet manufacturing, magnetic materials, etc., can solve the problem of shallow depth of grain boundary diffusion

Active Publication Date: 2021-09-14
JIANGSU UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the dense microstructure of sintered NdFeB magnets, the depth of grain boundary diffusion is relatively shallow, and the general industrial use of grain boundary diffusion technology can only diffuse magnets with a thickness of less than 5mm.

Method used

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  • Preparation method of neodymium-iron-boron magnet with large-depth grain boundary diffusion
  • Preparation method of neodymium-iron-boron magnet with large-depth grain boundary diffusion
  • Preparation method of neodymium-iron-boron magnet with large-depth grain boundary diffusion

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Effect test

Embodiment 1

[0023] A method for preparing a large depth grain boundary diffuse NdFeB magnet, including the following steps:

[0024] Step 1, select the NICE iron magnet of the commercial grade N52, cut N52 magnets into 10 × 10 × 5 (c-axis) mm 3 The surface oxide layer was placed with sandpaper, and clean with acetone.

[0025] Step 2, the magnet produced by steps is immersed in liquid nitrogen in -196 ° C for 20 minutes;

[0026] Step three, the magnet processed by step deeper is taken out from liquid nitrogen to increase the temperature of the magnet to room temperature;

[0027] Step 4, repeat steps 2 and step three 3 times;

[0028] Step 5. The magnet surface after step four is applied to the low melting point alloy DY. 70 Cu 30 Powder, put it in a vacuum furnace to 1 × 10 -2 PA, then elevated temperature to 800 ° C, heat insulation 1H;

[0029] Step 6. The magnet after the diffusion process in step five is lowered at 450 ° C for 2 hours, and the vacuum is set to 1 × 10 -2 PA.

Embodiment 2

[0038] A method for preparing a large depth grain boundary diffuse NdFeB magnet, including the following steps:

[0039] Step 1, select the sintered NdFeB magnet of the commercial grade N52, cut N52 magnets into 10 × 10 × 15 (c-axis) mm 3 The surface oxide layer was placed with sandpaper, and clean with acetone.

[0040] Step 2, the magnet produced by the step is immersed in liquid nitrogen in liquid nitrogen for 40 minutes;

[0041] Step three, the magnet processed by step deeper is taken out from liquid nitrogen to increase the temperature of the magnet to room temperature;

[0042] Step four, repeat steps 2 and steps three 4 times;

[0043] Step 5, the magnet surface is applied to the surface of the magnet surface to apply low melting point alloy TB 70 Cu 30 Powder, put it in a vacuum furnace to 1 × 10 -3 PA, then elevated temperature to 900 ° C, heat insulation 10h;

[0044] Step 6. The magnet after the step five diffusion is lowered at 480 ° C for 1 h, and the vacuum is set t...

Embodiment 3

[0054] A method for preparing a large depth grain boundary diffuse NdFeB magnet, including the following steps:

[0055] Step 1, select the sintered NdFeB magnet of the commercial grade N52, cut N52 magnets into 10 × 10 × 10 (c-axis) mm 3 The surface oxide layer was placed with sandpaper, and clean with acetone.

[0056] Step 2, the magnets formed by the steps were immersed in liquid nitrogen in liquid nitrogen in liquid nitrogen for 30 minutes;

[0057] Step three, the magnet processed by step deeper is taken out from liquid nitrogen to increase the temperature of the magnet to room temperature;

[0058] Step 4, repeat steps 2 and step three 5 times;

[0059] Step 5, the magnet surface after step four is applied to the low melting point alloy DYF 3 Powder, put it in a vacuum furnace to 1 × 10 -3 PA, then elevated temperatures to 950 ° C, heat insulation 5h;

[0060] Step 6, the magnet after the diffusion process in step five is lowered at 520 ° C for 6 hours, and the vacuum is se...

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Abstract

The invention discloses a preparation method of a neodymium-iron-boron magnet with large-depth grain boundary diffusion. The method comprises the following steps: immersing a sintered neodymium-iron-boron magnet block in liquid nitrogen at -196 DEG C for deep cooling treatment, then taking out the magnet, and naturally heating to room temperature' repeating the steps for 3-5 times, and performing subzero treatment before grain boundary diffusion of the neodymium-iron-boron magnet; and carrying out grain boundary diffusion treatment on the magnet by using a diffusion source rich in heavy rare earth elements. According to the method, the technical problem that the grain boundary diffusion depth of the neodymium-iron-boron magnet is small can be effectively solved, the neodymium-iron-boron magnet which is large in thickness, low in heavy rare earth content, high in coercive force and high in magnetic energy product can be prepared, and the application range of the grain boundary diffusion technology of the sintered neodymium-iron-boron magnet is widened.

Description

Technical field [0001] The present invention relates to a method for preparing a large depth grain boundary diffusion of NdFe boron magnets, in the field of rare earth permanent magnet materials. Background technique [0002] Nd-Fe-b) Permanent magnet materials have been published in the early 1980s. The current NICB is still a kind of permanent magnet material with the highest magnetic energy, has been widely used in aerospace, power electronics, Medical instruments, transportation and other fields. In recent years, environmental and energy supply has become increasingly prominent, and efficient and sustainable development has become a world-wide consensus. In this context, new energy vehicles, wind power, energy-saving air conditioners are rapidly developed, and the energy-saving efficient permanent magnet motor prepared by NdFeB magnets is advantageous to support the development of these industries. However, the permanent magnet motor and the permanent magnet motor are in oper...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F41/02H01F1/057
CPCH01F41/0293H01F1/0577
Inventor 陈夫刚
Owner JIANGSU UNIV OF SCI & TECH
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