Method for preparing sintered neodymium iron boron by adding nanometre aluminium powder

A nano-aluminum powder and NdFeB technology, applied in the field of rare earth magnetic materials, can solve problems such as limited resources, high mining costs, and performance degradation of NdFeB magnets Br, etc., and achieve the effect of reducing production costs

Inactive Publication Date: 2015-04-29
NINGBO HONGLEI MAGNETICS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The addition of a large amount of heavy rare earths such as dysprosium and terbium can greatly improve the intrinsic coercive force of the magnet, but Dy 2 Fe 14 B and Tb 2 Fe 14 The magnetic polarization of B magnets is low, and the addition of heavy rare earths such as dysprosium and terbium leads to a significant decline in the performance of NdFeB magnets such as Br.
Moreover, heavy rare earths such as dysprosium and terbium are scarce resources, with high mining costs and limited resources.

Method used

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  • Method for preparing sintered neodymium iron boron by adding nanometre aluminium powder

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] According to the following formula (PrNd) 30 Gd 1 co 1.0 Al 0.8 Cu 0.1 B 0.98 Fe bal (Mass percentage) Weigh the raw materials, and the raw materials that have been weighed are smelted at 1500 ° C in a vacuum quick-setting furnace with a vacuum degree of 0.5 Pa, and cast into flakes after the smelting is complete;

[0026] Put the above flakes in a hydrogen crushing furnace at 540°C for hydrogen crushing, hydrogen crushing for 4.5 hours to obtain a powder, and then use a jet mill to make a fine powder with an average particle size of 4 μm under the protection of nitrogen with an oxygen content of less than 200 ppm;

[0027] Add nano-aluminum powder with an average particle size of 50nm to the micropowder of NdFeB according to the ratio of 0.5wt%, and sieve through a sieve for a 200-mesh powder sieving machine after mixing evenly;

[0028] Put the sieved fine powder into the molding press mold under the protection of inert gas and apply a 1.5T magnetic field for or...

Embodiment 2

[0031] According to the following formula (PrNd) 30 Gd 1 co 1.0 Al 0.9 Cu 0.1 B 0.98 Febal (Mass percentage) Weigh the raw materials, and the raw materials that have been weighed are smelted at 1480 ° C in a vacuum quick-setting furnace with a vacuum degree of 0.6 Pa, and cast into flakes after the smelting is complete;

[0032] Put the above flakes in a hydrogen crushing furnace at 535°C for hydrogen crushing, hydrogen crushing for 4 hours to obtain a powder, and then use a jet mill to make a fine powder with an average particle size of 3.5 μm under the protection of nitrogen with an oxygen content of less than 200 ppm;

[0033] Add aluminum powder with an average particle size of 80nm to the micropowder of NdFeB according to the ratio of 0.3wt%, and sieve through a sieve for a 150-mesh powder sieving machine after mixing evenly;

[0034] Put the sieved fine powder into the molding press mold under the protection of an inert gas and apply a 1.6T magnetic field for orient...

Embodiment 3

[0037] According to the following formula (PrNd) 29 Gd 2 co 1.0 Al 0.9 Cu 0.1 B 0.98 Fe bal (Mass percentage) Weighing raw materials, the raw materials weighed are smelted at 1450°C in a vacuum quick-setting furnace with a vacuum degree of 0.3Pa, and cast into flakes after the smelting is complete;

[0038] Put the above flakes in a hydrogen crushing furnace at 550°C for hydrogen crushing, hydrogen crushing for 4 hours to obtain a powder, and then use a jet mill to make a fine powder with an average particle size of 5 μm under the protection of nitrogen with an oxygen content of less than 200 ppm;

[0039] Add aluminum powder with an average particle size of 10nm to the micropowder of NdFeB according to the ratio of 0.2wt%, and sieve through a sieve for a 300-mesh powder sieving machine after mixing evenly;

[0040] Put the sieved fine powder into the molding press mold under the protection of inert gas and apply a 2.0T magnetic field for orientation. After orientation, ...

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Abstract

The invention relates to a method for preparing sintered neodymium iron boron by adding nanometre aluminium powder, belonging to the technical field of rare earth magnetic material. The method comprises the following steps of: weighting the raw materials according to the following prescription: RxMyBzFe1-x-y-z (x=29-35wt%, y=0-4wt%, z=0.9-1.1wt%), wherein R is selected from one or several of La, Ce, Pr, Nd, Gd, Ho and Dy, and M is selected from one or several of Co, Al, Cu, Nb, Zr and Ga; pouring the smelted raw materials into melt-spinning sheets; hydrogen-smashing the melt-spinning sheets to obtain the powders and airflow-milling the powders into micro powders; adding the aluminium powders with the average grading of 10-100nm into the micro powders according to a proportion of 0.1-1wt% and mixing; pressing and moulding, and isostatic pressing processing the mixed powders into blanks; sintering, tempering to obtain the sintered neodymium iron boron magnets. According to the invention, the residual magnetism fall is relatively little and the production cost is low while the coercive force of the neodymium iron boron magnet is improved.

Description

technical field [0001] The invention relates to a method for preparing sintered NdFeB by adding nanometer aluminum powder, belonging to the technical field of rare earth magnetic materials. technical background [0002] NdFeB permanent magnet alloy, because of its high remanence, high coercive force and high magnetic energy product, has been applied in many aspects such as computer hard disk drives, motors, human magnetic resonance imagers, and audio devices. The preparation methods of NdFeB permanent magnet materials mainly include sintering, thermal deformation and bonding. The magnetic properties of bonded NdFeB are generally low due to the addition of binders. However, the traditional sintered NdFeB has poor temperature stability, low magnetization and low corrosion resistance due to the inhomogeneity of the structure, the existence of non-magnetic phases, and the coarse grains induced by high-temperature sintering. [0003] In the traditional sintered NdFeB magnet pro...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F1/057H01F1/08B22F1/00B22F3/16
Inventor 张宏芳
Owner NINGBO HONGLEI MAGNETICS
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