Preparation method of grain boundary diffusion heavy rare earth neodymium iron boron magnet and neodymium iron boron magnet

Abstract

The invention relates to a neodymium iron boron magnet and discloses a preparation method of a grain boundary diffusion heavy rare earth neodymium iron boron magnet and a neodymium iron boron magnet.The neodymium iron boron powders are pressed into a neodymium iron boron rough blank, and then are immersed in a heavy rare earth source molten mass. The heavy rare earth source molten mass proactively permeates the neodymium iron boron rough blank. The solid solution and permeation are generated between the heavy rare earth source molten mass and the neodymium iron boron rough blank so as to fillgaps and defects in the neodymium iron boron rough blank. Further, heavy rare earth elements are subjected to grain boundary diffusion in the neodymium iron boron magnet, to improve the grain boundary diffusion efficiency of the heavy rare earth elements, so that the grain boundary diffusion heavy rare earth element process becomes feasible for strengthening the coercive force of the neodymium iron boron magnet with large thickness, and a neodymium iron boron magnet having a thickness greater than 5 mm and a coercive force enhancement effect higher than that of the existing grain boundary diffusion heavy rare earth element process is obtained.

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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