Method for preparing ultrafine grained high performance anisotropic Nd-Fe-B permanent magnet

Abstract

The invention provides a method for preparing an ultrafine grained high performance anisotropic Nd-Fe-B permanent magnet. In this method, the nanocrystalline Nd-Fe-B powder is subjected to hot pressing treatment to obtain an isotropic magnet, and then the isotropic Nd-Fe-B magnet is subjected to low temperature thermal deformation to obtain an anisotropic Nd-Fe-B magnet having an ultrafine grainedstructure. Compared with the prior art, the invention adopts low temperature conditions for thermal deformation, and effectively suppresses the grain growth of the magnet in the existing high temperature thermal deformation technology; the obtained anisotropic magnet has an ultrafine grained structure; and the deformation uniformity of the magnet in the height direction is improved, and the performance of the magnet is improved.

Description

technical field

[0001] The invention belongs to the technical field of magnetic materials, in particular to a method for preparing an anisotropic single-phase NdFeB permanent magnet. Background technique

[0002] As a key functional material, NdFeB permanent magnets are widely used in various fields such as aerospace, transportation, national defense, medical equipment, computers, and electronic communications. The level of development in the direction of miniaturization, high efficiency, and energy conservation has become an important basis for the development of high-tech, emerging industries, and social progress. Especially under the stimulation of today's world theme of energy conservation and environmental protection, rare earth permanent magnet motors have developed rapidly due to their applications in energy-saving and new energy fields such as wind power generation, new energy vehicles, energy-saving elevators, energy-saving air conditioners, etc. application market...

Examples

Embodiment 1

[0028] In this example, the raw material is commercial MQU-F quick-quenching powder, and the anisotropic single-phase NdFeB permanent magnet block material is prepared by hot pressing and hot deformation method, as follows:

[0029] (1) The nanocrystalline MQU-F powder was pressed into a vacuum induction hot pressing furnace to obtain an isotropic magnet. The specific molding conditions are: the vacuum degree before heating up is better than 4×10 -2 Pa, then heat up at a heating rate of 80-150° C. / min to a pressing temperature of 650° C. for hot pressing at a pressing pressure of 210 MPa, and hold the pressure for 3 minutes after hot pressing.

[0030] (2) Put the isotropic magnet obtained in (1) into the Cu sheath and then put it into the mold, and press and deform it to the predetermined size in a vacuum induction hot-pressing furnace at 550°C to obtain Anisotropic NdFeB magnets. The specific deformation process is: vacuumize the sample chamber to 5×10 before thermal defor...

Embodiment 2

[0032] In this embodiment, the raw materials are exactly the same as those in Example 1, and the anisotropic single-phase NdFeB permanent magnet block material is prepared by hot pressing and thermal deformation method, as follows:

[0033] (1) is exactly the same as the step (1) of embodiment 1;

[0034] (2) It is basically the same as step (2) of Example 1, except that the deformation temperature is 500°C.

technical field

[0001] The invention belongs to the technical field of magnetic materials, in particular to a method for preparing an anisotropic single-phase NdFeB permanent magnet. Background technique

[0002] As a key functional material, NdFeB permanent magnets are widely used in various fields such as aerospace, transportation, national defense, medical equipment, computers, and electronic communications. The level of development in the direction of miniaturization, high efficiency, and energy conservation has become an important basis for the development of high-tech, emerging industries, and social progress. Especially under the stimulation of today's world theme of energy conservation and environmental protection, rare earth permanent magnet motors have developed rapidly due to their applications in energy-saving and new energy fields such as wind power generation, new energy vehicles, energy-saving elevators, energy-saving air conditioners, etc. application market...

Examples

Embodiment 1

[0028] In this example, the raw material is commercial MQU-F quick-quenching powder, and the anisotropic single-phase NdFeB permanent magnet block material is prepared by hot pressing and hot deformation method, as follows:

[0029] (1) The nanocrystalline MQU-F powder was pressed into a vacuum induction hot pressing furnace to obtain an isotropic magnet. The specific molding conditions are: the vacuum degree before heating up is better than 4×10 -2 Pa, then heat up at a heating rate of 80-150° C. / min to a pressing temperature of 650° C. for hot pressing at a pressing pressure of 210 MPa, and hold the pressure for 3 minutes after hot pressing.

[0030] (2) Put the isotropic magnet obtained in (1) into the Cu sheath and then put it into the mold, and press and deform it to the predetermined size in a vacuum induction hot-pressing furnace at 550°C to obtain Anisotropic NdFeB magnets. The specific deformation process is: vacuumize the sample chamber to 5×10 before thermal defor...

Embodiment 2

[0032] In this embodiment, the raw materials are exactly the same as those in Example 1, and the anisotropic single-phase NdFeB permanent magnet block material is prepared by hot pressing and thermal deformation method, as follows:

[0033] (1) is exactly the same as the step (1) of embodiment 1;

[0034] (2) It is basically the same as step (2) of Example 1, except that the deformation temperature is 500°C.

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