High-corrosion-resistance sintered neodymium-iron-boron-based permanent magnet material prepared by doping zinc nano-particles and preparation method thereof

A technology of nano-particles and permanent magnetic materials, applied in the direction of magnetic materials, magnetic objects, electrical components, etc., can solve problems such as micro-cracks, poor uniformity of coating methods, and low bonding force

Active Publication Date: 2012-07-11
BEIJING UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the coating method still has problems such as poor uniformity,...

Method used

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  • High-corrosion-resistance sintered neodymium-iron-boron-based permanent magnet material prepared by doping zinc nano-particles and preparation method thereof
  • High-corrosion-resistance sintered neodymium-iron-boron-based permanent magnet material prepared by doping zinc nano-particles and preparation method thereof
  • High-corrosion-resistance sintered neodymium-iron-boron-based permanent magnet material prepared by doping zinc nano-particles and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] Use quick-setting technology to change the composition to Nd 13.7 Fe bal Al 0.3 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. Then, 1.0% by weight Zn nano powder with an average particle size of 100 nm 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 2.5T and pressed into shape. Then put the compact into a high-vacuum sintering furnace, and heat up to 1120°C for sintering for 3 hours. Afterwards, heat treatment is carried out in two stages, wherein the temperature of the primary heat treatment is 930°C for 2 hours, and the temperature of the secondary heat treatment is 580°C for 1 hour. That is, a sintered NdFeB-based magnet with high corrosion resistance is obtained.

Embodiment 2

[0020] Use quick-setting technology to change the composition to Nd 12.8 Dy 0.5 Fe bal Al 1.0 Nb 0.3 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 5 microns by using a hydrogen crushing-jet milling process. After that, 4.0% by weight Zn nano powder with an average particle size of 500 nm 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 2.5T and pressed into shape. Then put the compact into a high-vacuum sintering furnace and heat up to 1020°C for sintering for 4 hours. Afterwards, heat treatment is carried out in two stages, wherein the temperature of the primary heat treatment is 830°C for 3 hours, and the temperature of the secondary heat treatment is 480°C for 3 hours. That is, sintered NdFeB magnets with high corrosion resistance are obtained.

[0021] comparative exam...

Embodiment 3

[0028] Use quick-setting technology to change the composition to Nd 12.3 Dy 1.0 Fe bal Nb 0.2 co 0.5 Al 0.1 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 4 microns by using a hydrogen crushing-jet milling process. Then, 3.0% by weight of Zn nano-powder with an average particle size of 300 nanometers was added to the above-mentioned initial powder, and the two powders were uniformly mixed by a mixer. The uniformly mixed powder was oriented in a magnetic field of 2.5T and pressed into shape. Then put the compact into a high-vacuum sintering furnace and heat up to 1080°C for 2 hours for sintering. Then carry out secondary heat treatment, wherein the temperature of primary heat treatment is 900°C for 1 hour; the temperature of secondary heat treatment is 630°C for 2 hours. That is, sintered NdFeB magnets with high corrosion resistance are obtained.

[0029] comparative example

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Abstract

The invention provides a high-corrosion-resistance sintered neodymium-iron-boron-based permanent magnet material prepared by doping zinc nano-particles and a preparation method thereof, belonging to the technical field of magnetic materials. The preparation method comprises the following steps of: adding Zn nano powder with the average diameter being 100-500 nm into neodymium-iron-boron-based powder with the size of 3-5 microns and uniformly mixing, wherein the adding amount of the Zn nano power is 1.0-4.0%; and then, orientating in a magnetic field of 2.5 T and carrying out compression molding; placing the mixture into a sintering furnace; raising the temperature to 1020-1120 DEG C and sintering for 2-4 hours; and finally, carrying out heat treatment in two stages, wherein the temperature of the first-state heat treatment is 830-930 DEG C and the time is 1-3 hours, the temperature of the second-state heat treatment is 480-630 DEG C and the time is 1-3 hours; and finally obtaining a high-corrosion-resistance sintered neodymium-iron-boron-based permanent magnet. According to the invention, the corrosion resistance of the magnet is improved and the effect that the magnet does not need to be coated is achieved. The corrosion weight loss is lower than 2 mg/cm<3> in a high-pressure accelerated corrosion experiment under the conditions of 121 DEG C, 0.2 MPa and 500 hours.

Description

technical field [0001] The invention relates to a method for preparing a neodymium-iron-boron-based permanent magnet material with high corrosion resistance, belonging to the technical field of magnetic materials. Background technique [0002] Sintered NdFeB magnets are the most magnetic permanent magnet materials so far, widely used in many fields such as electronics, electromechanical, instrumentation and medical treatment, and are the fastest growing permanent magnet materials with the best market prospects in the world today. However, one of the most obvious disadvantages of sintered NdFeB magnets is poor corrosion resistance, which greatly limits the application of such magnets in high temperature and humid environments. At present, there are two main ways to improve the corrosion resistance of sintered NdFeB magnets: alloying method and anti-corrosion coating method. The alloying method refers to the addition of trace amounts of alloying elements during the alloy smel...

Claims

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Application Information

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IPC IPC(8): H01F1/057B22F9/04B22F3/16
Inventor 岳明刘卫强孙超张东涛张久兴
Owner BEIJING UNIV OF TECH
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