Method for improving performance of sintered NdFeB magnet

A magnetic performance, NdFeB technology, applied in the direction of magnetic materials, magnetic objects, inductance/transformer/magnet manufacturing, etc., can solve the problems of limited performance improvement, high diffusion activation energy, shallow diffusion depth, etc., to achieve reduced dosage, The process is simple and the effect of reducing the dosage

Inactive Publication Date: 2019-09-06
JIANGXI UNIV OF SCI & TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The heavy rare earth elements Dy and Tb, as important elements for improving the coercive force, can effectively increase the anisotropy constant of the 2:14:1 phase magnetocrystal, but their price is high
The traditional surface deposition simply uses rare earth oxides or fluorides to increase the coerc

Method used

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  • Method for improving performance of sintered NdFeB magnet
  • Method for improving performance of sintered NdFeB magnet
  • Method for improving performance of sintered NdFeB magnet

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] (1) Slice the sintered NdFeB magnet into 10*20*6 mm blocks.

[0023] (2) Use 600 CW, 1000CW, 1500CW, and 2000CW sandpaper to polish the 6 surfaces of the magnet in sequence, and then put them in alcohol for ultrasonic vibration cleaning; then ultrasonically degrease the magnet in a degreasing solution at 50 °C 3min, followed by washing with water for 5-15 s.

[0024] (3) Place the magnet in a nitric acid solution with a concentration of 3% and shake it for 10-20 s. After taking it out, wash it twice with water for 5-15 s each time, and then perform ultrasonic vibration treatment until the magnet is observed. After the surface oxide skin has completely fallen off, it is taken out and dried at a temperature of 40°C for 20 minutes. Other methods can also be used to completely peel off the oxide skin on the surface of the magnet.

[0025] (4) MgO powder and Dy 2 o 3 The powder is mixed, and the ratio of the atomic number of Mg to the atomic number of Dy in the mixture i...

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Abstract

The invention discloses a method for improving performance of a sintered NdFeB magnet. According to the method, a metal oxide is reduced with hydrogen under a high temperature by means of the characteristic of low-melting metal oxide, low-melting metal is sequentially obtained according to a reduction sequence, a discontinuous crystal boundary rare-earth phase of a magnet surface layer is preferably diffused and recovered, a continuous low-melting point rare-earth phase is obtained and is used as a rapid diffusion passage of a heavy rare-earth element, the diffusion depth of the heavy rare-earth element in the magnet is effectively improved, the dosage of the heavy rare-earth element is reduced, the improvement of magnet coercivity is achieved, meanwhile, the dosage of the heavy rare-earthelement is also remarkably reduced, the method is simple in process, is easy to implement and has a wide application prospect.

Description

technical field [0001] The invention belongs to the technical field of rare earth permanent magnet materials, and in particular relates to a method for improving the magnetic properties of sintered NdFeB magnets. Background technique [0002] NdFeB permanent magnets are known as the "Magnetic King" due to their excellent magnetic properties, and are widely used in aerospace, wind power generation, energy-saving home appliances, electronic appliances, and new energy vehicles. And with the continuous improvement of manufacturing technology and the improvement of people's awareness of environmental protection, it has attracted the attention of the market in the three major fields of energy conservation and environmental protection, new energy, and new energy vehicles. Application prospect. [0003] For magnets, coercive force is an important index to evaluate the magnetic properties of Nd-Fe-B permanent magnet materials. The heavy rare earth elements Dy and Tb, as important e...

Claims

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Application Information

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IPC IPC(8): H01F41/02H01F1/057
CPCH01F41/0293H01F1/0577
Inventor 杨牧南钟淑伟卢耀军杨斌罗三根
Owner JIANGXI UNIV OF SCI & TECH
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