A preparation method of regenerative sintered Nd-Fe-B permanent magnet

A permanent magnet, NdFeB technology, used in magnetic objects, inductance/transformer/magnet manufacturing, magnetic materials, etc., can solve the problems of high price and low resource reserves, and achieve low price, high resource reserves and high proportion. Effect

Active Publication Date: 2019-01-11
EARTH PANDA ADVANCE MAGNETIC MATERIAL
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In order to make regenerative magnets have a higher coercive force, the current doped rare earth powders are mainly Pr, Nd, Dy, Tb, etc., with less resource reserves and higher prices.

Method used

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  • A preparation method of regenerative sintered Nd-Fe-B permanent magnet

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] (1) Use sand blasting + ultrasonic cleaning to remove the coating / plating layer, oxide layer and other pollutants on the surface of the waste sintered NdFeB permanent magnet, and then use hydrogen crushing + jet mill to crush it into an average particle size of 3.2 μm the initial magnetic powder;

[0022] (2) According to the ratio of 98.5:1.5, the initial magnetic powder and DyH with an average particle size of 3.0 μm x After the powders were mixed, they were heat-treated at 600 °C for 10 h with constant stirring to make DyH x The Dy atoms in the NdFeB powder diffuse into the surface layer of waste NdFeB powder to obtain modified magnetic powder;

[0023] (3) According to the ratio of 2:100, Ce with an average particle size of 2.5 μm 80 Al 20 Mixed alloy powder and modified magnetic powder to obtain mixed magnetic powder;

[0024] (4) Place the mixed magnetic powder in a 1.7T magnetic field to make a green compact through orientation pressing;

[0025] (5) The gre...

Embodiment 2

[0034] (1) Use dilute hydrochloric acid cleaning + ultrasonic cleaning to remove the coating / plating layer, oxide layer and other pollutants on the surface of the waste sintered NdFeB permanent magnet, and then use hydrogen crushing + ball milling to crush it into an average particle size of 3.5 μm the initial magnetic powder;

[0035] (2) According to the ratio of 98:2, the initial magnetic powder and TbF with an average particle size of 2.5 μm 3 After mixing the powders, heat treatment at 650 °C for 8 hours with constant stirring, so that the TbF 3 The Tb atoms in the NdFeB powder diffuse into the surface layer of waste NdFeB powder to obtain modified magnetic powder;

[0036] (3) According to the ratio of 2:100, CeH with an average particle size of 2.9 μm x The powder is mixed with modified magnetic powder to obtain mixed magnetic powder;

[0037] (4) Place the mixed magnetic powder in a magnetic field above 2.0T to make a green compact through orientation pressing;

[...

Embodiment 3

[0045] (1) Use sandpaper to remove the coating / plating layer, oxide layer and other pollutants on the surface of the waste sintered NdFeB permanent magnet, and then use hydrogen crushing + jet milling to crush it into initial particles with an average particle size of 2.6μm magnetic powder;

[0046] (2) According to the ratio of 99:1, the initial magnetic powder and TbH with an average particle size of 2.2 μm x After the powders were mixed, they were heat-treated at 600 °C for 5 h with constant stirring to make the TbH x The Tb atoms in the NdFeB powder diffuse into the surface layer of waste NdFeB powder to obtain modified magnetic powder;

[0047] (3) LaH with an average particle size of 2.5 μm was added at a ratio of 4:100 x The powder is mixed with modified magnetic powder to obtain mixed magnetic powder;

[0048] (4) Place the mixed magnetic powder in a magnetic field above 1.8T to make a green compact through orientation pressing;

[0049](5) The green compact is sin...

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Abstract

The invention provides a preparation method of regenerated sintered Nd-Fe-B permanent magnet, which comprises the following steps of: carrying out surface pretreatment on waste sintered Nd-Fe-B permanent magnet, and then crushing the waste Nd-Fe-B permanent magnet into magnetic powder with an average particle size of 2.0-4.0 mum; 2 to 99.5 to 0.5, so that that heavy rare earth atom diffuse into the surface layer of the magnetic powder to obtain the modified magnetic powder; 100 to 5:100 of rich and high-abundance rare earth powder and modified magnetic powder according to mass ratio to obtainmixed magnetic powder. The mixed magnetic powder is placed in a magnetic field with a magnetic field strength of more than 1.5 T, and then the magnetic powder is pressed into a compact by the orientedmoulding method. The regenerative sintered Nd-Fe-B permanent magnet is prepared by high temperature sintering and tempering. The regenerative sintered Nd-Fe-B permanent magnet prepared by the invention has high performance, low cost and high recovery efficiency for waste magnets.

Description

technical field [0001] The invention belongs to the field of magnetic materials, and in particular relates to a method for preparing regenerative sintered NdFeB permanent magnets by using high-abundance rare earths. Background technique [0002] Rare earth is an important non-renewable resource and an important constituent element of rare earth permanent magnet materials. As the highest performance and most widely used rare earth permanent magnet material, sintered NdFeB permanent magnet material has achieved great development, and its annual output has continued to increase, consuming a large amount of rare earth resources. On the other hand, during the production and processing of sintered NdFeB products, from the initial raw materials to the final products, each process will inevitably produce scrap materials. In addition, a large number of finished products such as NdFeB motors are scrapped. There is a huge amount of waste sintered NdFeB magnets. Using waste sintered N...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F41/02H01F1/057
CPCH01F1/0577H01F41/0266H01F41/0293
Inventor 冯泉妤周志国陈静武黄秀莲衣晓飞
Owner EARTH PANDA ADVANCE MAGNETIC MATERIAL
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