Rare-earth permanent magnet with high magnetic performance and high electric resistance and preparation method thereof

Abstract

The invention relates to the technology of rare-earth permanent magnet materials, and particularly discloses a rare-earth permanent magnet with high magnetic performance and high electric resistance and a preparation method thereof. The permanent magnet comprises the following components in part by mass: 100 parts of neodymium iron boron and samarium cobalt type magnetic powder with granularity of 20 to 300 microns, 0.1 to 5 parts of titanate coupling agent, 1 to 10 parts of bisphenol A epoxy resin and 0.2 to 2 parts of bisphenol F epoxy resin; the components are evenly mixed, and then are molded to form a cured substance at the temperature field of between 20 and 200 DEG C under the orientation field of which the magnetic field intensity is 0.5 to 3T; and the preparation method for the rare-earth permanent magnet comprises the following steps: coupling the surface of the magnetic powder and the coupling agent, then mixing the magnetic powder, the coupling agent and the resin, drying and grinding the mixture, and molding the mixture at the temperature field under the orientation field. The magnetic performance of the permanent magnet of the invention can keep higher level and has no obvious decline compared with the magnetic performance of the high-end adhesive NdFeB magnet, and the electric resistance of the magnet is improved by over 10 times; and the permanent magnet has no obvious temperature rise under the 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 can