Method for improving magnetic performance of sintered neodymium-iron-boron magnet

Abstract

The invention relates to a method for improving magnetic performance of a sintered neodymium-iron-boron magnet. The method is suitable for sintered neodymium-iron-boron magnets with various components. The method comprises low-melting-point metal or alloy grain boundary repairing, heavy rare earth element grain boundary diffusion and corresponding heat treatment technologies. According to the method, the character of the low melting point of an alloy is utilized, the surface-layer discontinuous grain boundary rare earth phase of the magnet is preferably diffused and repaired, a continuous low-melting-point rare earth phase is obtained and serves as a channel for rapid diffusion of heavy rare earth elements, the diffusion depth of the heavy rare earth elements in the magnet is effectively improved, the usage amount of the heavy rare earth elements is reduced, the coercivity of the magnet is improved, and wide application value is achieved.

Description

technical field [0001] The invention belongs to the technical field of rare earth permanent magnet materials, and in particular relates to a method for improving the magnetic properties of sintered NdFeB magnets. Background technique [0002] NdFeB permanent magnets are known as the "Magnetic King" due to their excellent magnetic properties, and are widely used in aerospace, wind power generation, energy-saving home appliances, electronic appliances, and new energy vehicles. And with the continuous improvement of manufacturing technology and the improvement of people's awareness of environmental protection, it has attracted the attention of the market in the three major fields of energy conservation and environmental protection, new energy, and new energy vehicles, and has become a key material for the realization of the "Made in China 2025" development plan. 10-20% rapid growth rate, showing good application prospects. [0003] For magnets, coercive force is an important i...

AI Technical Summary

Problems solved by technology

The heavy rare earth elements Dy and Tb, as important elements for improving the coercive force, can effectively increase the anisotropy constant of the 2:14:1 phase magnetocrystal, but their price is high

Therefore, the coercive force is generally increased by depositing and diffusing the heavy rare earth elements Dy and Tb on the surface, and the manufacturing cost of the magnet is reduced. However, the concentration of heavy rare earth elements decreases from the surface to the inside, and the diffusion depth is shallow, so the performance improvement is limited.

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