A kind of preparation method of sintered NdFeB permanent magnet material

Abstract

The invention relates to a method for preparing a sintered rare earth permanent magnetic material. The method includes the steps of material preparation, smelting, hydrogen decrepitation, jet milling, forming, sintering, machining and surface treatment. The smelting step includes material loading, vacuumizing, pre-heating, argon filling, smelting, refining, casting, cooling and taking out of a furnace. The technological process is optimized in the rare earth permanent magnetic material manufacturing process, so that the rare earth permanent magnetic material prepared through the preparation method has the product advantages of being high in grade, uniformity, work temperature and corrosion resistance, low in weight loss and the like, and has great popularization significance.

Description

technical field [0001] The invention relates to the technical field of rare earth permanent magnet materials, in particular to a preparation method of a sintered NdFeB permanent magnet material. Background technique [0002] Rare earth permanent magnet material is an alloy composed of samarium, neodymium mixed rare earth metals and transition metals (such as cobalt, iron, etc.), pressed and sintered by powder metallurgy, and magnetized by a magnetic field. [0003] Rare earth permanent magnets are divided into samarium-cobalt (SmCo) permanent magnets and neodymium-iron-boron (NdFeB) permanent magnets. The magnetic energy product of the SmCo magnet is between 15 and 30MGOe, and the magnetic energy product of the NdFeB permanent magnet is between 27 and 60MGOe. Known as the "Permanent Magnet King", it is currently the most magnetic permanent magnet material. Samarium-cobalt permanent magnets, despite their excellent magnetic properties, contain rare earth metal samarium and r...

AI Technical Summary

Problems solved by technology

[0005] Although the magnetic properties of sintered NdFeB permanent magnet materials are very high, they have defects such as low coercive force and poor corrosion resistance, and the temperature resistance of permanent magnet materials is poor.

[0006] For example, the Chinese invention patent (application number: 201210395959.0) proposes a sintered rare earth permanent magnet material and its preparation method, which solves how to improve the coercive force and service temperature of the sintered rare earth permanent magnet material without losing remanence and reducing the Material cost, it is proposed to add a grain boundary infiltration process in the preparation steps of sintered rare earth permanent magnet materials, smelting and coarse crushing or between coarse crushing and fine crushing, although increasing the grain boundary infiltration process will affect the coercive force and use of sintered rare earth permanent magnet materials The temperature has been increased, but this process is complicated, the environment is harsh, new mechanical equipment needs to be invested, the processing procedure is complicated, and defective products are prone to appear. Therefore, how to solve the problem of improving the performance of sintered NdFeB permanent magnet materials to make them better Being developed is a great driving force for the applicant to propose the present invention

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