Method for producing rare earth permanent magnet with high ce content by one-step heat treatment technology

A technology of rare earth permanent magnets and rare earth permanent magnets, which is applied in the field of production of rare earth permanent magnets with high Ce content, can solve the problems of restricting the development and utilization of light rare earth elements, difficulty in obtaining commercial magnets, and destroying the core-shell structure, so as to alleviate the magnetic dilution effect , Protect from damage, improve the effect of magnet coercive force

Active Publication Date: 2019-02-05
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, when NdCeFeB magnets are prepared by the dual main phase process, if the two-step heat treatment is still used, the core-shell structure formed by the dual main phases will be destroyed and the magnetic properties will be reduced. For example, for a dual main phase magnet with 27wt.% Ce substitution, After two-step heat treatment, the magnetic properties are B r =12.7kGs,H cj =8.1kOe, (BH) max = 39.8MGOe, with the increase of Ce substitution, the magnetic properties are severely reduced, and it is difficult to meet the requirements of commercial magnets, which limits the development and utilization of light rare earth elements

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0010] 1) It will be calculated in mass percentage, and the composition is (Pr, Nd) 15.25 Ce 15.25 Fe 67.11 Al 1.39 B 1 main phase A and

[0011] (Pr,Nd) 30.55 Fe 67.11 Al 1.39 B 1 The two main phase alloys of the main phase B are separately proportioned, and two kinds of flakes with a thickness of 0.3mm are obtained by using the quick-setting casting strip technology;

[0012] 2) Prepare the alloy powder with an average particle size of 3.1 μm by subjecting the two main phase flakes to hydrogen explosion and jet milling;

[0013] 3) In terms of mass percentage, after mixing 54wt.% of the main phase A alloy powder and 46wt.% of the main phase B alloy powder evenly, under the protection of nitrogen, the magnetic powder is oriented and formed under a magnetic field of 2T, and subjected to 17MPa cold isostatic pressed into a green body;

[0014] 4) Put the green body in a vacuum sintering furnace for sintering, the sintering temperature is 1040°C, the sintering time is ...

Embodiment 2

[0017] 1) It will be calculated in mass percentage, and the composition is (Pr, Nd) 15.25 Ce 15.25 Fe 67.11 co 1.39 B 1 main phase A and

[0018] (Pr,Nd) 30.55 Fe67.11 co 1.39 B 1 The two main phase alloys of the main phase B are batched separately, and two types of flakes with a thickness of 0.3mm are obtained by using the quick-setting casting strip technology;

[0019] 2) The alloy powder with an average particle size of 3.3 μm was prepared by hydrogen explosion and jet milling processes of the two main phase flakes;

[0020] 3) In terms of mass percentage, after mixing 72wt.% of the main phase A alloy powder and 28wt.% of the main phase B alloy powder evenly, the magnetic powder is oriented and formed under a 2T magnetic field under the protection of nitrogen, and subjected to 17MPa cold isostatic pressed into a green body;

[0021] 4) Put the green body in a vacuum sintering furnace for sintering, the sintering temperature is 1040°C, the sintering time is 3h, and...

Embodiment 3

[0024] 1) It will be calculated in mass percentage, and the composition is (Pr, Nd) 15.25 Ce 15.25 Fe 67.11 Ga 1.39 B 1 Main Phase A and (Pr,Nd) 30.55 Fe 67.11 Ga 1.39 B 1 The two main phase alloys of the main phase B are batched separately, and two types of flakes with a thickness of 0.3mm are obtained by using the quick-setting casting strip technology;

[0025] 2) The alloy powder with an average particle size of 3.3 μm was prepared by hydrogen explosion and jet milling processes of the two main phase flakes;

[0026] 3) In terms of mass percentage, after mixing 90wt.% of the main phase A alloy powder and 10wt.% of the main phase B alloy powder evenly, under the protection of nitrogen, the magnetic powder is oriented and formed under a magnetic field of 2T, and subjected to 17MPa cold isostatic pressed into a green body;

[0027] 4) Put the green body in a vacuum sintering furnace for sintering, the sintering temperature is 1040°C, the sintering time is 2.5h, and t...

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Abstract

The invention discloses a method for producing a rare-earth permanent magnet high in Ce content through a one-step heat treatment technology. The mass percent general formula of the magnet is (Pr, Nd)xCey(Fe1-zMz)100-x-y-wBw, wherein M is one or more of Nb, V, Ti, Co, Cr, Mo, Mn, Ni, Ga, Zr, Ta, Ag, Au, Al, Pb, Cu and Si, 29<=x+y<=33, 1 / 4<=y / x<=3 / 2, 0.5<=z<=2, and 0.8<=w<=1.5. Based on the double main phase alloy technology, low temperature sintering is adopted, heat treatment is conducted only for one step, and then the rare-earth permanent magnet high in Ce content is produced. 60 by weight% Ce substitution amount can be achieved by using the method, the balanced use of rare-earth elements is promoted, the production processes are reduced, and the cost is effectively reduced.

Description

technical field [0001] The invention relates to a method for producing rare earth permanent magnets with high Ce content by one-step heat treatment technology. 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. As the world's largest exporter of rare earths, in recent years, it has carried out macro-control on the rare earth industry, implemented export quotas, levied and gradually raised export tariffs, strengthened environmental supervision, implemented protective mining of rare earth resources, and the era of cheap competition for rare earth products has passed. Rare earth prices have been rising all the way, and the globa...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01F41/02H01F1/057B22F3/04B22F3/10B22F3/24
CPCB22F3/04B22F3/10B22F3/24B22F2003/248H01F1/0573H01F1/0576H01F1/0577H01F41/0266H01F41/0293
Inventor 严密李江涛罗伟张玉晶金佳莹
Owner ZHEJIANG UNIV
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