Method for preparing permanent magnet through low-temperature orientation forming and hot-pressing densification of omnidirectional anisotropic neodymium iron boron magnetic powder

By using a method of low-temperature orientation molding and hot-pressing densification of omnidirectional NdFeB magnetic powder, the problems of insufficient remanence, intrinsic coercivity and maximum energy product of omnidirectional NdFeB permanent magnets have been solved, achieving a synergistic improvement in high remanence, high coercivity and high squareness, thereby improving the stability of the device and the utilization rate of the energy product.

CN122136119APending Publication Date: 2026-06-02GUANGDONG XINMEI SUPERHARD MATERIAL CO LTD
0 Cites 0 Cited by

Patent Information

Application Number
CN202610512643.7
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2026-04-17
Publication Date
2026-06-02

AI Technical Summary

Technical Problem

Existing omnidirectional NdFeB permanent magnets suffer from poor remanence, intrinsic coercivity, maximum energy product, and squareness, making it difficult to achieve a compatible match between high remanence and high coercivity. Furthermore, their poor microstructure consistency leads to insufficient device stability during service.

Method used

A method for preparing omnidirectional NdFeB magnetic powder by low-temperature orientation molding and hot pressing densification is adopted, which includes steps such as alloy melting in a high-purity argon atmosphere, vacuum annealing, hydrogen explosion treatment, axial static magnetic field treatment, dilute nitric acid washing, modified suspension treatment, and hot pressing treatment. The axial static magnetic field guides the growth of oriented crystal nuclei, the modified nanosheets are coated, and the hot pressing process improves the wettability and density of grain boundaries.

Benefits of technology

It significantly improves the remanence, intrinsic coercivity and maximum energy product of omnidirectional NdFeB permanent magnets, optimizes the squareness of the demagnetization curve, and enhances the effective energy product utilization rate and device stability of the magnets.

✦ Generated by Eureka AI based on patent content.
Patent Text Reader

Abstract

The invention discloses a method for preparing a permanent magnet through low-temperature orientation forming and hot-pressing densification of omnidirectional anisotropic neodymium iron boron magnetic powder, and relates to the technical field of permanent magnet materials. The method comprises the following steps: melting Fe, B-Fe alloy and Co, adding Nd, Ga, Al and Cu, melting, casting, carrying out vacuum annealing, crushing, treating in a hydrogen atmosphere at 300-350 DEG C, carrying out vacuum treatment at 350 DEG C, treating in a hydrogen atmosphere at 800-820 DEG C and 80 kPa, carrying out vacuum treatment in an axial constant static magnetic field at 800 DEG C, 0.08-0.1 Pa and 2.2-2.5 T, discharging, pre-treating with a dilute nitric acid aqueous solution, and carrying out vacuum treatment at a temperature of 300-350 DEG C, and finally, carrying out warm-pressing treatment, vacuum degreasing treatment and hot-pressing treatment to obtain the omnidirectional anisotropic neodymium-iron-boron permanent magnet with excellent residual magnetism, intrinsic coercive force, maximum magnetic energy product and squareness at the same time.
Need to check novelty before this filing date? Find Prior Art