Preparation method of high-performance sintered neodymium-iron-boron magnet

A NdFeB, high-performance technology, applied in the direction of magnetic objects, inductors/transformers/magnet manufacturing, magnetic materials, etc., can solve the problems of magnet performance degradation, neodymium-rich phase purge outflow, etc., to improve coercive force, good Economic benefits, effects of enhanced remanence and maximum energy product

Active Publication Date: 2020-06-05
TAIYUAN UNIVERSITY OF SCIENCE AND TECHNOLOGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For magnets with lower rare earth content, the content of Nd-rich phase in the grain boundary area is less, and the thermal expansion gas of tens of MPa is sintered at a high sintering

Method used

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  • Preparation method of high-performance sintered neodymium-iron-boron magnet

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0030] Example 1

[0031] A method for preparing high-performance sintered NdFeB magnets includes the following steps:

[0032] The NdFeB alloy micropowder (PrNd) is prepared by the vacuum rapid solidification stripping and hydrogen breaking process 30.1 Cu 0.2 Ga 0.2 Co 0.5 Al 0.2 Zr 0.2 Nb 0.1 Fe 67.7 B 0.8 ; Add 1.2wt% lubricant (tributyl borate), 1.2wt% antioxidant (organic esters and aviation gasoline mixture), 0.5wt% dispersant (polyethylene glycol) to the prepared alloy powder Material 2h; put the mixed raw materials into a jet mill to make powder with an average particle size of 3μm, then add 0.2wt% lubricant (tributyl borate), mix for 2h; place the mixed magnetic powder in a magnetic field with a magnetic field strength of 2T Medium orientation, simultaneous compression molding, the magnetic field direction of the magnetic field is perpendicular to the pressure direction of the compression molding, the blank after the compression molding is processed by cold isostatic pres...

Example Embodiment

[0033] Example 2

[0034] The neodymium-iron-boron alloy powder in this example 2 is the same as that in example 1, and the other preparation process conditions remain unchanged. The only difference is that the sintering temperature during the high-temperature sintering process is 1050°C. Room temperature performance: remanence Br=13.9kGs, maximum magnetic energy product (BH)max=47.8MGOe, coercivity Hcj=17.8kOe.

Example Embodiment

[0044] Example 3

[0045] A method for preparing high-performance sintered NdFeB magnets includes the following steps:

[0046] Nd-Fe-B alloy powder Nd is prepared by vacuum quick-setting stripping and hydrogen breaking process 23.5 Pr 7 Dy 0.5 Ga 0.1 Co 1 Al 0.1 Zr 0. 2 Cu 0.1 Fe 66.63 B 0.97 ; Add 0.8wt% lubricant (tributyl borate), 0.75wt% antioxidant (organic esters and aviation gasoline mixture), 1.2wt% dispersant (polyethylene glycol) to the prepared alloy powder 3h; Put the mixed fine powder into the jet mill to make the powder, the average particle size is 3μm, then add 0.2wt% lubricant (tributyl borate), mix for 3h; apply the reverse magnetic field 2T to the magnetic powder first, and then apply the forward direction The magnetic field is 2T, the negative magnetic field is applied 6 times, and then the compression molding is performed. The magnetic field direction of the magnetic field is perpendicular to the pressure direction of the compression molding. After the compres...

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Abstract

A preparation method of a high-performance sintered neodymium-iron-boron magnet belongs to the technical field of rare earth permanent magnet materials and comprises the following steps: preparing single alloy or main alloy and auxiliary alloy micro powder by adopting vacuum rapid hardening melt-spinning and hydrogen decrepitation processes; adding a lubricating agent, an antioxidant and a dispersing agent, and mixing; grinding powder by airflow, adding a lubricant into magnetic powder, mixing, orienting the magnetic powder in a magnetic field, pressing and molding, and carrying out isostaticcool pressing treatment; carrying out heat preservation and deflation treatment in three temperature sections; cooling to 300-500 DEG C, introducing high-purity argon with the pressure intensity of 2-10 MPa, and carrying out hot pressing treatment; sintering at high temperature, naturally cooling to 800-900 DEG C, introducing room-temperature argon or liquid argon, and performing rapid cooling; and then carrying out two-stage heat treatment and argon rapid cooling respectively. According to the invention, the density of the final magnet is improved by improving the density before high-temperature sintering, so that the residual magnetism and the maximum magnetic energy product are enhanced. By reducing the sintering temperature, the coercive force can be obviously improved under the conditions of high residual magnetism and high magnetic energy product. The method has good economic benefits and is suitable for industrial production.

Description

technical field [0001] The invention belongs to the technical field of rare earth permanent magnet materials, and in particular relates to a preparation method of a high-performance sintered NdFeB magnet. Background technique [0002] In the preparation of high-performance sintered NdFeB magnets, it is necessary to obtain high remanence Br or high maximum energy product (BH) max , improving the degree of grain orientation is a key. Generally, an appropriate amount of antioxidant, lubricant and dispersant are added to the powder before magnetic field compression molding. During the magnetic orientation process, the lubricant and dispersant are beneficial to the rotation and fluidity of the powder, and are beneficial to the magnetic powder in the orientation magnetic field. A high degree of orientation is obtained. Increasing the magnetic field intensity of the orientation magnetic field is also conducive to improving the orientation degree of the magnetic micropowder. Duri...

Claims

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Application Information

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IPC IPC(8): H01F1/057H01F41/02B22F3/10B22F3/14
CPCH01F1/0577H01F41/0253H01F41/0266B22F3/1007B22F3/14B22F2003/145B22F2998/10B22F1/10B22F2003/248B22F3/04B22F3/02B22F2009/044B22F9/023
Inventor 胡季帆张敏刚吴铭张克维宗朔通
Owner TAIYUAN UNIVERSITY OF SCIENCE AND TECHNOLOGY
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