A rare earth permanent magnet with high magnetic performance and high resistivity and its preparation method

Abstract

The invention relates to a rare earth permanent magnet material technology, and specifically introduces a rare earth permanent magnet with high magnetic performance and high resistivity and a preparation method thereof. 100 parts, 0.1-5 parts of titanate coupling agent, 1-10 parts of bisphenol A epoxy resin, and 0.2-2 parts of bisphenol F epoxy resin are uniformly mixed at 20-200 ℃ temperature field and magnetic field strength: The cured product is formed under the orientation field of 0.5-3T; the preparation process includes coupling the surface of the magnetic powder with the coupling agent, then mixing with the resin, drying and grinding, and forming under the temperature field and the orientation field. Compared with the high-end bonded NdFeB magnet, the magnetic performance of the permanent magnet of the present invention maintains a relatively high level, and the magnetic performance is not significantly decreased, and the magnet resistivity is increased by more than 10 times; there is no obvious temperature rise under a high-frequency alternating field for 1 hour.

Description

technical field [0001] The invention relates to a technology in the field of rare earth permanent magnet materials, in particular to a rare earth permanent magnet with high magnetic performance and high resistivity and a preparation method thereof. Background technique [0002] Compared with sintered permanent magnets, bonded magnets have many advantages such as high cost performance, convenient forming of special-shaped magnets, high processing precision, good toughness, small magnetic deviation, and easy miniaturization. Therefore, bonded magnets have been widely used in the fields of computers, mobile communications, high-end audio, micro-special motors, sensors, and magnetoelectric instruments. When the bonded magnet is applied in a high-frequency alternating field, due to its low resistivity, strong eddy currents are likely to be generated on the surface of the magnet, resulting in a rapid increase in the temperature of the magnet, and the magnetic properties of the mag...

AI Technical Summary

Problems solved by technology

When the bonded magnet is applied in a high-frequency alternating field, due to its low resistivity, strong eddy currents are likely to be generated on the surface of the magnet, resulting in a rapid increase in the temperature of the magnet, and the magnetic properties of the magnet will be seriously affected. Therefore, ordinary bonded rare earth It is difficult for permanent magnets to be applied in high-frequency fields

[0003] In the prior art, one method is a multi-pole electrical insulation R-Fe-B permanent magnet introduced in Japanese Patent Publication No. 8-279407, which is a sintered magnet, which is formed after the magnet is sintered. The method of vacuum evaporation is used to coat a layer of 2-10 μm polyimide resin film on the surface of the magnet to improve its insulation performance, but the magnet obtained by this method still cannot be used under a higher frequency alternating magnetic field. Avoid the loss of magnetic properties caused by the internal heating of the eddy current of the magnet

In addition, Chinese patents such as CN97121777.7 and CN02157615.7 all mentioned the method of adding insulating additives to rare earth permanent magnets to improve their electrical insulation performance. From the results, the electrical insulation performance has indeed been significantly improved, but due to The addition of a large amount of insulating additives has caused a serious decline in the magnetic properties of the magnet, and at the same time its molding process is a non-oriented molding method, which also makes it difficult to further improve the magnetic properties of the magnet, making it difficult for the magnet mentioned in the invention to be widely used in practice