Method for evaluating grain boundary diffusion depth of neodymium-iron-boron magnet

Abstract

The invention discloses a method for the evaluating grain boundary diffusion depth of a neodymium-iron-boron magnet, which comprises the steps of processing the neodymium-iron-boron magnet treated bya grain boundary diffusion process to a standard size, and grinding the surface of the processed neodymium-iron-boron magnet to prepare a group of sample wafers with different grinding thicknesses; and detecting the ground neodymium-iron-boron magnet through an X-ray fluorescence spectrometer to obtain the X fluorescence intensity of the diffusion element on the test surface of the neodymium-iron-boron magnet, and evaluating the grain boundary diffusion depth of the neodymium-iron-boron magnet according to the relationship between the grinding thickness and the X fluorescence intensity of theelement to be detected. A series of neodymium-iron-boron magnet samples with different grain boundary diffusion depths are ground to be 0.8 mm in thickness, the series of sample wafers serve as reference sample wafers, and a grain boundary diffusion depth-fluorescence intensity comparison table of the reference sample wafers is formed. An unknown sample is ground according to the same method as the reference sample wafer, the X-ray fluorescence intensity of grain boundary diffusion elements of the orientation surface of the unknown sample is measured through an X-ray fluorescence spectrometer,and compared with the reference sample wafer, the grain boundary diffusion depth of the neodymium-iron-boron magnet can be rapidly evaluated.

Description

technical field [0001] The invention relates to the technical field of detection of rare earth permanent magnet materials, in particular to a method for evaluating the diffusion depth of the grain boundary of an NdFeB magnet. Background technique [0002] As an important functional material, NdFeB rare earth permanent magnet materials are widely used in new energy vehicles, wind power generation and other fields, which put forward higher requirements for the coercive force of NdFeB rare earth permanent magnet materials. The traditional preparation of sintered NdFeB with high coercivity is achieved by adding a large amount of heavy rare earth Dy / Tb during the smelting process. However, due to the high price of heavy rare earth, the rare earth permanent magnet industry has used grain boundary diffusion technology to reduce the addition of heavy rare earth elements in recent years. The amount increases the coercive force of the material while ensuring that the residual magnetis...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the problem that the existing analysis method for the grain boundary diffusion depth of NdFeB magnets has a long flow and cumbersome operation, the present invention provides an evaluation method for the grain boundary diffusion depth of NdFeB magnets, which can analyze the grain boundary diffusion depth of NdFeB magnets. In-depth rapid assessment to judge whether the NdFeB magnet grain boundary diffusion products meet the requirements

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