Unlock instant, AI-driven research and patent intelligence for your innovation.

Low-heavy-rare-earth high-coercivity sintered neodymium-iron-boron magnet and preparation method thereof

A high coercive force, NdFeB technology, applied in the direction of magnetic objects, inductors/transformers/magnet manufacturing, magnetic materials, etc., can solve the problem of sintered NdFeB magnets, such as the effect is not obvious, to achieve resistance reduction, reduce the preparation process , evenly distributed effect

Active Publication Date: 2020-12-01
HEFEI UNIV OF TECH +1
View PDF13 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the grain boundary diffusion technology is only suitable for thinner magnets, affected by the depth of grain boundary diffusion, the effect is not obvious for sintered NdFeB magnets with a thickness ≥ 30mm

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Low-heavy-rare-earth high-coercivity sintered neodymium-iron-boron magnet and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] A method for preparing a low-weight rare earth high-coercivity sintered NdFeB magnet, comprising the following steps:

[0025] (1) Milling:

[0026] The NdFeB coarse powder crushed by hydrogen is jet-milled under the protection of low-temperature helium gas, the temperature of the low-temperature helium gas is 20°C, and the NdFeB alloy powder A is obtained, and the average particle size of the NdFeB alloy powder A is is 1.8 μm.

[0027] (2) Molding:

[0028] NdFeB alloy powder A and heavy rare earth dysprosium powder B with an average particle size of 0.5 μm are alternately and evenly placed in the lower cavity of the mold. That is, first put NdFeB alloy powder A evenly in the lower cavity of the mold, the thickness of powder A is 5 μm, and then evenly cover a layer of heavy rare earth dysprosium powder B, the thickness of powder B is 0.1 μm, continue Repeat and evenly cover the NdFeB alloy powder A and the heavy rare earth dysprosium powder B until the size requirem...

Embodiment 2

[0034] A method for preparing a low-weight rare earth high-coercivity sintered NdFeB magnet, comprising the following steps:

[0035] (1) Milling:

[0036] The NdFeB coarse powder crushed by hydrogen is jet-milled under the protection of low-temperature helium gas, and the temperature of the low-temperature helium gas is 15°C to obtain NdFeB alloy powder A. The average particle size of NdFeB alloy powder A is 2.0 μm.

[0037] (2) Molding:

[0038] NdFeB alloy powder A and dysprosium hydride powder B with an average particle size of 1.0 μm are alternately and evenly placed in the lower cavity of the mold. That is, first put the NdFeB alloy powder A evenly in the lower cavity of the mold, the thickness of the powder A is 6 μm, and then evenly cover a layer of dysprosium hydride powder B, the thickness of the powder B is 0.2 μm, and continue to repeat 1. Uniformly covering the NdFeB alloy powder A and the dysprosium hydride powder B until the size requirements of the magnet ar...

Embodiment 3

[0044] A method for preparing a low-weight rare earth high-coercivity sintered NdFeB magnet, comprising the following steps:

[0045] (1) Milling:

[0046] The NdFeB coarse powder crushed by hydrogen is jet-milled under the protection of low-temperature helium gas, and the temperature of the low-temperature helium gas is 10°C to obtain NdFeB alloy powder A, wherein the average particle size of NdFeB alloy powder A is 3.0 μm.

[0047] (2) Molding:

[0048] NdFeB alloy powder A and terbium fluoride powder B with an average particle size of 1.5 μm are alternately and evenly placed in the lower cavity of the mold. That is, first put the NdFeB alloy powder A evenly in the lower cavity of the mold, the thickness of the powder A is 8 μm, and then evenly cover a layer of terbium fluoride powder B, the thickness of the powder B is 0.3 μm, continue Repeat and evenly cover the NdFeB alloy powder A and terbium fluoride powder B until the size requirements of the magnet are met, and per...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
Thicknessaaaaaaaaaa
Thicknessaaaaaaaaaa
Login to View More

Abstract

The invention discloses a low-heavy-rare-earth high-coercivity sintered neodymium-iron-boron magnet and a preparation method thereof. The preparation method specifically comprises the following stepsof preparation of neodymium-iron-boron alloy powder, forming, grain boundary diffusion, sintering and tempering heat treatment. In the magnet forming process, neodymium-iron-boron alloy powder and heavy rare earth-rich powder are alternately and uniformly placed in a forming mold in sequence, and then grain boundary diffusion treatment is carried out on the neodymium-iron-boron compact, and due tothe fact that the neodymium-iron-boron compact is in a semi-compact state, resistance borne by migration of heavy rare earth Dy and Tb in the compact is remarkably reduced, and distribution of the Dyand the Tb in the magnet is more uniform. And the problems of residual magnetism and magnetic energy product reduction caused by heavy rare earth Dy and Tb added in the alloy smelting process are effectively avoided, and the problem that the grain boundary diffusion effect of a large magnet is poor is solved.

Description

technical field [0001] The invention relates to the field of rare earth permanent magnet materials, in particular to a low-weight rare earth high coercivity sintered NdFeB magnet and a preparation method thereof. Background technique [0002] As a magnetic functional material, rare earth permanent magnet materials play an important role in various fields of social development. Among them, sintered NdFeB magnets have good comprehensive performance and high cost performance, and are widely used in wind power generation, automobile industry, medical equipment, household appliances, aerospace and other fields. They are known as the contemporary "magnet king" and occupy half of the permanent magnet materials. . With the development of modern technology, information, and emerging industries towards integration, intelligence, and miniaturization, the requirements for the performance of sintered NdFeB magnets are getting higher and higher. However, the low Curie temperature and po...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): H01F1/057H01F41/02
CPCH01F1/0577H01F41/0253H01F41/0293H01F41/0266Y02E10/72
Inventor 吴玉程曹玉杰徐光青刘帮张鹏杰崔接武
Owner HEFEI UNIV OF TECH