Method for preparing sintered neodymium iron boron permanent magnet material with high coercive force and high corrosion resistance

A high coercivity, permanent magnet material technology, applied in the direction of magnetic materials, inorganic material magnetism, magnetic objects, etc., can solve the problems of grain shedding, overall alloy corrosion, etc., to achieve reduced corrosion resistance, good corrosion resistance, The effect of reducing the scale

Active Publication Date: 2013-04-24
BEIJING UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Its corrosion will lead to the main phase Nd 2 Fe 14 The bonding interface between the B grains disappears, and the grains fall off, which eventually leads to the overall corrosion of the alloy

Method used

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  • Method for preparing sintered neodymium iron boron permanent magnet material with high coercive force and high corrosion resistance
  • Method for preparing sintered neodymium iron boron permanent magnet material with high coercive force and high corrosion resistance
  • Method for preparing sintered neodymium iron boron permanent magnet material with high coercive force and high corrosion resistance

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Use quick-setting technology to change the composition to Nd 13.5 Fe bal al 0.4 B 6 (atomic percent content) of the alloy is prepared as flakes, and then the powder is made into a powder with an average particle size of 3 microns by using a hydrogen crushing-jet milling process. Dysprosium-zinc alloy powder (DyZn 5 ) to the above initial powder, and use a mixer to mix the two powders evenly. The uniformly mixed powder was oriented in a magnetic field of 1.8T and pressed into shape. Then put the compact into a high-vacuum sintering furnace and heat up to 1060°C for sintering for 3 hours. Afterwards, secondary heat treatment is carried out, wherein the temperature of the primary heat treatment is 950° C. for 2 hours, and the temperature of the secondary heat treatment is 580° C. for 1 hour. That is, a sintered magnet was obtained.

[0018] Billy 1

[0019] Adopt the same process as embodiment 1 to prepare the Nd of undoped dysprosium-zinc alloy powder particle 13...

Embodiment 2

[0025] Use quick-setting technology to change the composition to Nd 12.5 Fe bal Al 0.5 Nb 0.2 B 6 (atomic percent) of the alloy is prepared as flakes, and then the powder is made into a powder with an average particle size of 5 microns by using a hydrogen crushing-jet milling process. Then, 1.0% by weight dysprosium-zinc alloy (DyZn) powder with an average particle size of 3 microns was added to the above initial powder, and the two powders were uniformly mixed by a mixer. The uniformly mixed powder was oriented in a magnetic field of 1.8T and pressed into shape. Then put the compact into a high-vacuum sintering furnace, and heat up to 1000°C for sintering for 4 hours. Then carry out secondary heat treatment, wherein the temperature of primary heat treatment is 900°C for 3 hours; the temperature of secondary heat treatment is 460°C for 2 hours. That is, a sintered magnet was obtained.

Embodiment 2 and comparative example 2

[0029] Table 2 Example 2 and Comparative Example 2 magnet magnetic properties and corrosion resistance comparison

[0030]

[0031] The above results illustrate that for sintered NdFeB magnets with the same composition, the coercive force of the magnet prepared by adding dysprosium-zinc alloy powder particles according to the present invention is significantly improved compared with that of the undoped magnet. In addition, the remanence and energy product of the two magnets are equivalent. The corrosion resistance of the magnet is significantly improved.

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Abstract

The invention discloses a method for preparing a sintered neodymium iron boron permanent magnet material with high coercive force and high corrosion resistance, and belongs to the technical field of a magnetic material. The method comprises the steps of adding dysprosium zinc nano powder of which the mean grain size is 1-10 microns to neodymium iron boron powder with the grain size of 3-5 microns and evenly mixing, wherein the adding amount is 0.3-3.0%, and then orienting, pressing and molding in 1.8T magnetic field; putting in a vacuum sintering furnace, then heating and sintering at 1000-1100 DEG C for 3-5 hours, and finally carrying out thermal treatment by two levels, wherein the primary thermal treatment temperature is 850-950 DEG C; the time is 1-3 hours; the secondary thermal treatment temperature is 460-600 DEG C, and the time is 1-3 hours, finally obtaining the sintered neodymium iron boron permanent magnet material with high coercive force and high corrosion resistance. The corrosion resistance of the magnetic body is greatly improved when the coercive force of the magnetic body is obviously improved, and the rare earth content is also reduced.

Description

technical field [0001] A method for preparing a neodymium-iron-boron permanent magnet material with high coercive force and high corrosion resistance belongs to the technical field of magnetic materials. Background technique [0002] NdFeB permanent magnet materials have been developed since the middle and late 1980s. They are new materials encouraged by the state, mainly including sintered and bonded rare earth permanent magnet materials. They have become an indispensable part of various industries in the national economy, especially the electronics and automobile industries There are many types of alternative basic materials, which are widely used in many fields such as electronics, automobiles, computers, electric power, machinery, energy, environmental protection, national defense, and medical equipment. development of. [0003] Since the emergence of NdFeB series rare earth permanent magnet materials, they have developed rapidly in just a few decades. People have conti...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C33/02C22C38/00B22F9/04B22F3/16H01F1/057H01F1/08H01F41/02
Inventor 刘卫强岳明孙超张东涛张久兴
Owner BEIJING UNIV OF TECH
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