Preparation method of permanent magnet material

Abstract

The invention provides a preparation method of a permanent magnet material. The preparation method provided by the invention comprises a coating process and a permeation process, wherein a material containing a rare-earth element coats the surfaces of sintered neodymium-iron-boron magnets; the thickness of each sintered neodymium-iron-boron magnet in one direction is at least less than 10mm; the sintered neodymium-iron-boron magnets are regularly arranged; with respective surfaces with the maximum area as contact surfaces, the sintered neodymium-iron-boron magnets tightly contact one another under the pressure action; and then the sintered neodymium-iron-boron magnets are subjected to heat treatment. By the preparation method provided by the invention, the rare-earth element can permeate evenly and the permeability is high. In addition, by the preparation method provided by the invention, the coercive force of the permanent magnet material can be greatly improved while the residual magnetism is reduced slightly.

Description

technical field [0001] The invention relates to a manufacturing method of a permanent magnet material, in particular to a manufacturing method of a sintered NdFeB permanent magnet. Background technique [0002] As the world pays more and more attention to reducing energy consumption, energy conservation and emission reduction has become the focus of various countries. Compared with non-permanent magnet motors, permanent magnet motors can improve the energy efficiency ratio. Therefore, in order to reduce energy consumption, Nd-Fe-B permanent magnet materials are used in air-conditioning compressors, electric vehicle hybrid vehicles and other fields. to make the motor. Due to the high operating temperature of these motors, the magnets are required to have a high intrinsic coercive force; and, in order to increase the magnetic flux density of the motor, the magnets are also required to have a high magnetic energy product. [0003] It is difficult to meet the requirements of h...

AI Technical Summary

Problems solved by technology

The feature of this method is to heat the material containing heavy rare earths to form steam. The disadvantages are that the equipment is expensive and the evaporation efficiency is low. The actual comparison results show that this method is not as effective as the previous method for increasing the intrinsic coercive force Hcj.

[0007] CN101615459A discloses a method for improving the performance of sintered NdFeB permanent magnets by diffusing heavy rare earth compounds in the grain boundaries of quick-setting sheets. Infiltration treatment is performed before sintering. The heavy rare earths collected in the intergranular phase will diffuse into the main phase, resulting in the averaging of heavy rare earths, and the effect is poor