Method for improving neodymium, cerium, iron and boron sintered magnet coercivity by adding neodymium hydride

A sintered magnet, neodymium-cerium-iron-boron technology, applied in the manufacture of magnetic objects, magnetic materials, inductors/transformers/magnets, etc., can solve the problems of not meeting the requirements of commercial magnets, optimize the microstructure and improve the grain boundary Phase distribution, effect of simple process

Inactive Publication Date: 2017-05-24
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But the coercive force is only 9.26kOe, still not up to the requirements of commercial magnets

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] 1) The two main phase alloys are prepared by four alloy processes of vacuum induction melting, quick solidification casting, hydrogen explosion and jet milling respectively. The diameter of the powder particles is about 3.5 μm, and the main alloy is expressed in atomic percentage , whose alloy composition is Nd 32.5 Fe bal B 1 and Nd 16.25 Ce 16.25 Fe bal B 1 ;

[0036] 2) Mix the A main phase and B main phase alloy powders uniformly in a glove box under the protection of high-purity nitrogen at a mass percentage of 46:54 to obtain a mixed powder; put the mixed alloy powder in a 1.5T-2.0T Orientation molding is carried out under the magnetic field, and the green body is made into a green body by cold isostatic pressing of 17MPa;

[0037]3) Sinter the green body at 1045°C for 3 hours in a high-vacuum sintering furnace, perform primary tempering at 890°C for 2 hours, and perform secondary tempering at 465°C for 4 hours to obtain an NdCer-Fe-B magnet;

[0038] 4) m...

Embodiment 2

[0040] 1) The two main phase alloys are prepared by four alloy processes of vacuum induction melting, quick solidification casting, hydrogen explosion and jet milling respectively. The diameter of the powder particles is about 3.5 μm, and the main alloy is expressed in atomic percentage , whose alloy composition is Nd 32.5 Fe bal B 1 and Nd 16.25 Ce 16.25 Fe bal B 1 ;

[0041] 2) Hydrogen explosion of metal neodymium, and use mechanical ball milling method to grind it into a powder with a particle diameter of approximately 0.5-1.0 μm. The alloy is expressed in atomic percentage, and its composition is NdH x ;

[0042] 3) Mix the two main phase alloy powders and the neodymium hydride powder in a glove box under the protection of high-purity nitrogen according to the quality to obtain the mixed powder, wherein the mass percentage of the main phase A and the main phase B in the two main phase alloy powders It is 46:54, and the weight of neodymium hydride powder accounts f...

Embodiment 3

[0047] 1) The two main phase alloys are prepared by four alloy processes of vacuum induction melting, quick solidification casting, hydrogen explosion and jet milling respectively. The diameter of the powder particles is about 3.5 μm, and the main alloy is expressed in atomic percentage , whose alloy composition is Nd 32.5 Fe bal B 1 and Nd 16.25 Ce 16.25 Fe bal B 1 ;

[0048] 2) Hydrogen explosion of metal neodymium, and use mechanical ball milling method to grind it into a powder with a particle diameter of approximately 0.5-1.0 μm. The alloy is expressed in atomic percentage, and its composition is NdH x ;

[0049] 3) Mix the two main phase alloy powders and the neodymium hydride powder in a glove box under the protection of high-purity nitrogen according to the quality to obtain the mixed powder, wherein the mass percentage of the main phase A and the main phase B in the two main phase alloy powders It is 46:54, and the weight of neodymium hydride powder accounts f...

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Abstract

The invention discloses a method for improving neodymium, cerium, iron and boron sintered magnet coercivity by adding neodymium hydride. The method comprises the steps that on the basis of the dual-main-phase alloy technology and the crystal boundary technology, two-main-phase alloy and crystal boundary auxiliary alloy are separately designed, prepared and powdered, magnetic field compression, sintering and thermal sintering are performed after powder is mixed proportionally to obtain a magnet. The coercivity of the obtained neodymium, cerium, iron and boron sintered magnet is high, preparation is easy and convenient, operation is easy, and the raw material cost of the magnet is effectively lowered.

Description

technical field [0001] The invention relates to a method for increasing the coercive force of a sintered neodymium cerium iron boron magnet by adding neodymium hydride. Background technique [0002] Sintered NdFeB magnet is currently the permanent magnet material with the strongest magnetism, the widest application and the most rare earth consumption. It is widely used in high-tech fields such as information, energy, medical care, transportation and national defense. It is the most important rare earth functional material and the national economy. key basic materials. The rapid growth of NdFeB for many years has led to excessive consumption of elements such as Nd\Pr\Tb\Dy, which are highly dependent, while Ce and La with high abundance are rarely used. At present, efficient, reasonable and balanced utilization of rare earth resources is a major strategic demand of our country. Realizing the application of Ce in NdFeB can not only significantly reduce the production cost of...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F1/057H01F41/02B22F9/04B22F3/04B22F3/10
CPCH01F1/0576B22F3/04B22F3/10B22F9/04B22F2009/043H01F1/0577H01F41/0266
Inventor 吴凯云马天宇严密金佳莹
Owner ZHEJIANG UNIV
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