Preparation method of grain boundary diffused heavy rare earth NdFeB magnet and NdFeB magnet

Abstract

The invention relates to an NdFeB magnet, and discloses a preparation method of a grain boundary diffused heavy rare earth NdFeB magnet and the NdFeB magnet. The preparation method involves pressing NdFeB powder into a NdFeB rough billet and then immersing it in a heavy rare earth source for melting. solid solution and infiltration between the heavy rare earth source melt and the NdFeB rough billet, filling the gaps and defects in the NdFeB rough billet, and at the same time The heavy rare earth element diffuses in the grain boundary of the NdFeB rough blank, which improves the grain boundary diffusion efficiency of the heavy rare earth element, making it feasible for the grain boundary diffusion heavy rare earth element process to strengthen the coercive force of the thicker NdFeB magnet, and obtains A neodymium-iron-boron magnet with a thickness greater than 5mm and a coercivity enhancement effect higher than the existing process of grain boundary diffusion of heavy rare earth elements.

Description

technical field [0001] The invention relates to a neodymium-iron-boron magnet, in particular to a preparation method of a grain boundary diffused heavy rare earth neodymium-iron-boron magnet and the neodymium-iron-boron magnet. Background technique [0002] NdFeB permanent magnet materials are the most concerned rare earth application industry in my country's rare earth industry. With the development of science and technology and technological progress, the demand for high-performance NdFeB permanent magnet materials is becoming more and more extensive. In order to improve the coercive force and high-temperature usability of NdFeB, the commonly used method is to add a small amount of heavy rare earth elements (such as Dy, Tb, etc.) or optimize the process to refine the magnet grains. [0003] At present, the methods to reduce the usage of heavy rare earth mainly include double alloy process and grain boundary diffusion heavy rare earth element process. [0004] The double a...

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Problems solved by technology

[0010] However, this process is the same as the existing grain boundary diffusion heavy rare earth element process, and has the same disadvantages, that is, it is limited to making thinner magnetic parts (thickness generally does not exceed 5mm). When preparing large magnets, the grain boundary The effect of diffusing heavy rare earth elements is poor, and the coercive force improvement of NdFeB magnet materials is small, so it needs to be improved

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