Preparation method for high-coercivity sintered neodymium-iron-boron

A high coercive force, neodymium iron boron technology, applied in the direction of magnetic materials, magnetic objects, electrical components, etc., can solve the problem of coercive force rise and other problems, achieve the increase of intrinsic coercive force, prolong the service life, and increase the magnetic energy product Effect

Active Publication Date: 2014-07-30
SHENYANG SHENGSHI WUHUAN TECH CO LTD
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  • Abstract
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  • Application Information

AI Technical Summary

Problems solved by technology

It can be seen that although the high magnetic energy product of the magnet is very close to the theoretical value, the coercive force still has a lot of room for improvement.
[0003] The preparation technology of nanomaterials has been developed for decades, but there is still great room for development in the field of application technology of nanomaterials

Method used

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  • Preparation method for high-coercivity sintered neodymium-iron-boron

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Example 1: 50M

[0029] 1. Raw materials with a purity greater than 99% are classified as Nd 30 Fe 68.82 Cu 0.1 Ga 0.1 B 0.98 (wt%) ratio for batching, and then use intermediate frequency vacuum quick-setting throwing belt furnace to prepare alloy flakes with a thickness of 0.25-0.35mm;

[0030] 2. Put the alloy flakes in the reactor of the hydrogen crushing furnace to absorb hydrogen at room temperature for 2 hours, then heat to 550°C for 6 hours to dehydrogenate, and prepare coarse particles with a particle size of 60-80 mesh, and then add 1‰ of anti-oxidant (polyepoxide Ethylene allyl ether) mixed evenly for 10-30 minutes;

[0031] 3. Grind the coarse powder after the 2-step mixing by a QLMR-260G jet mill under a working pressure of 0.8 MPa to a fine powder with an average particle size of 2.5 μm;

[0032] 4. In an argon protective atmosphere, add Nd rare earth nano-additives with an average particle size of 55nm to the 3-step powder by using the jet method, ...

Embodiment 2

[0041] Example 2: 45H

[0042] 1. Raw materials with a purity greater than 99% are classified as PrNd 30.1 Fe 68.1 al 0.1 Cu 0.1 co 0.3 Nb 0.2 Ga 0.1 B 1.0 (wt%) ratio for batching, and then use intermediate frequency vacuum quick-setting throwing belt furnace to prepare alloy flakes with a thickness of 0.25-0.35mm;

[0043] 2. Put the alloy flakes in the reactor of the hydrogen crushing furnace to absorb hydrogen at room temperature for 2 hours, then heat to 550°C for 6 hours to dehydrogenate, and prepare coarse particles with a particle size of 60-80 mesh, and then add 1‰ of anti-oxidant (polyepoxide Ethylene allyl ether) mixed evenly for 10-30 minutes;

[0044] 3. Grind the coarse powder after the 2-step mixing by a QLMR-260G jet mill under a working pressure of 0.8 MPa to a fine powder with an average particle size of 2.5 μm;

[0045] 4. In an argon protective atmosphere, add Pr-Nd and Dy rare earth nano-additives with an average particle size of 50nm to the pow...

Embodiment 3

[0054] Example 3: 42H

[0055] 1. Raw materials with a purity greater than 99% are classified as PrNd 29.7 Fe 68.5 al 0.1 Cu 0.1 co 0.3 Nb 0.2 Ga 0.1 B 1.0 (wt%) ratio for batching, and then use intermediate frequency vacuum quick-setting throwing belt furnace to prepare alloy flakes with a thickness of 0.25-0.35mm;

[0056] 2. Put the alloy flakes in the reactor of the hydrogen crushing furnace to absorb hydrogen at room temperature for 2 hours, then heat to 550°C for 6 hours to dehydrogenate, and prepare coarse particles with a particle size of 60-80 mesh, and then add 1‰ of anti-oxidant (polyepoxide Ethylene allyl ether) mixed evenly for 10-30 minutes;

[0057] 3. Grind the coarse powder after the 2-step mixing by a QLMR-260G jet mill under a working pressure of 0.8 MPa to a fine powder with an average particle size of 2.5 μm;

[0058] 4. In an argon protective atmosphere, add Pr-Nd, Dy, and Ho rare earth nano-additives with an average particle size of 50nm to th...

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Abstract

The invention discloses a preparation method for high-coercivity sintered neodymium-iron-boron. The method specifically comprises the following steps: batching raw materials proportionally, and preparing a thin alloy sheet by using a medium-frequency vacuum rapid-hardening melt-spinning furnace; performing normal-temperature hydrogen absorption and heating dehydrogenation on the thin alloy sheet in a reaction kettle of a hydrogen decrepitating furnace to prepare coarse particles of which the particle size is 60-80 meshes; milling hydrogen-decrepitated coarse powder by using a jet mill to form fine powder of which the average particle size is 2.0-4.0 mu m; adding one or more rare-earth nano additives into the powder by using a jet method, and performing uniform mixing in the atmosphere of argon shielding; performing oriented molding and isostatic pressing on the mixed powder under the argon shielding through a 1.8-3.0T magnetic field; filling a green neodymium-iron-boron body into a vacuum sintering furnace in a closed glove box full of nitrogen, continuously sintering the green neodymium-iron-boron body for three times, quickly cooling the green neodymium-iron-boron body, and finally, aging the green neodymium-iron-boron body twice to prepare a corresponding neodymium-iron-boron magnet of which the performance meets the national standard. The method is low in cost, simple in process, energy-saving, environmentally-friendly, and high in rare-earth utilization rate.

Description

technical field [0001] The invention relates to the technical field of preparation of NdFeB permanent magnet materials, specifically a method for preparing high coercive force sintered NdFeB magnets by directly adding one or more rare earth nano-additives to generate grain boundary phases, especially for the preparation of ultra-high coercive force sintered NdFeB magnets. The coercive magnet method. Background technique [0002] At present, the prices of rare earth metals such as praseodymium (Pr), neodymium (Nd), dysprosium (Dy), terbium (Tb), holmium (Ho) and other raw materials have risen sharply. It is the industry's priority to reduce the use of rare earths, especially heavy rare earths, under the premise of ensuring performance. The top priority of development is also an important research direction in the next few years. Many scholars at home and abroad have conducted a lot of research based on this: In 2011, Japan adopted a new technology to obtain a magnet with a m...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F1/057H01F1/08B22F3/16
Inventor 张强冯泉张喜陈德忠张俊飞
Owner SHENYANG SHENGSHI WUHUAN TECH CO LTD
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