Preparation method of high-performance neodymium-iron-boron permanent magnet

Abstract

The invention belongs to the field of preparation of neodymium iron boron permanent magnets, and provides a preparation method of a high-performance neodymium-iron-boron permanent magnet. The preparation method comprises the following steps of: slicing a proper amount of sintered and non-tempered neodymium-iron-boron permanent magnet, removing oil, performing cleaning, drying, and putting the sintered and non-tempered neodymium-iron-boron permanent magnet into a vacuumized solvent dialysis chamber; putting a heavy rare earth substance into a constant-temperature and constant-pressure tank; pressurizing alcohol liquid in a solvent tank through a pressurizing pump and a heat exchanger, heating the alcohol liquid, making the alcohol liquid flow through the constant-temperature and constant-pressure tank, extracting the heavy rare earth substance in the constant-temperature and constant-pressure tank by utilizing a solvothermal synthesis method, and making the heavy rare earth substance flow into the solvent dialysis chamber; cooling the solvent dialysis chamber until the heavy rare earth substance is precipitated in pores of the neodymium-iron-boron permanent magnet in a needle-shaped nanometer stepped manner; slowly cooling the solvent dialysis chamber, depositing a compact rare earth deposition film on the surface of the magnet, and then carrying out heat treatment. The method can be used for treating the special-shaped neodymium-iron-boron permanent magnet, improve the diffusivity and reduce the carbon content in a heavy rare earth deposition film.

Description

technical field [0001] The invention relates to the field of preparation of NdFeB permanent magnets, in particular to a preparation method of high-performance NdFeB permanent magnets. Background technique [0002] In recent years, the application and development of NdFeB permanent magnet materials has been very rapid, and the success of the protection of NdFeB permanent magnet materials is one of the key technologies related to the promotion and application of materials. The material is mainly made of rare earth metals such as neodymium Nd, iron and boron through powder metallurgy process. As the strongest magnetic material at present, it has been widely used in electroplating devices, machinery, medical treatment, automobiles and other fields, and its application prospects are very broad. However, with the further increase in the price of heavy rare earth dysprosium and terbium, foreign NdFeB companies, especially Japanese companies, use evaporation (CN103597108) and coati...

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Problems solved by technology

[0006] In the prior art, the method of vapor deposition or coating has certain requirements on the specifications of the magnet, and the corresponding processing cannot be carried out for irregular products; when non-volatile cellulose acetate is added to the ethanol solution, its Carbonization, at the same time, the carbonization process will affect the diffusion channel and reduce the diffusion efficiency; the rare earth deposition film is easy to leave organic matter, which will increase the carbon content in the NdFeB magnet and affect the magnetic properties

[0007] In order to solve the problem that the specifications of the magnets are required by evaporation or coating, the irregular products cannot be processed accordingly; when non-volatile cellulose acetate is added to the ethanol solution, it will be carbonized during heat treatment, At the same time, the carbonization process will affect the diffusion channel and reduce the diffusion efficiency; the rare earth deposition film is easy to leave organic matter, which will increase the carbon content in the NdFeB magnet and affect the magnetic performance. The present invention provides a high-performance NdFeB permanent magnet. preparation method to solve this problem

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