Neodymium-iron-boron magnet and preparation method thereof

Abstract

The invention discloses a neodymium-iron-boron magnet and a preparation method thereof. The neodymium-iron-boron magnet consists of a neodymium-iron-boron matrix alloy and doped components, wherein the doped components are tin and aluminum nano particles; the doping amount of the tin nano particles accounts for 0.02-1.0 percent of the weight of the neodymium-iron-boron matrix alloy, and the doping amount of the aluminum nano particles accounts for 0.03-3.0 percent of the weight of the neodymium-iron-boron matrix alloy. The invention also discloses a preparation method of the neodymium-iron-boron magnet. Compared with the conventional neodymium-iron-boron magnet, the internal grasping coercive force of the neodymium-iron-boron magnet disclosed by the invention is improved by 8-20 percent, and the working temperature is increased by 30-50 DEG C; under the condition of the same performance, the content of heavy rare earth and the content of strategic metal cobalt are reduced, and the production cost is saved.

Description

technical field [0001] The invention relates to a magnetic material and a preparation method thereof, in particular to a sintered NdFeB magnet with high coercive force and high temperature stability, which is compositely added with tin and aluminum nanoparticles, and a preparation method thereof. Background technique [0002] Sintered NdFeB magnets have high remanence, magnetic energy product and coercive force, and have won the title of "Magnetic King". Household appliances, medical equipment, computer technology, microwave communication, electronics, electroacoustics, automation, aerospace and other fields, especially suitable for developing various replacement products with high performance, miniaturization and light weight. [0003] With the expansion of the application range, the requirements for the comprehensive performance of the magnet are getting higher and higher, especially the temperature stability. In some motors and automation equipment, when sintered NdFeB m...

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Problems solved by technology

However, this method needs to prepare the matrix alloy and the grain boundary phase alloy separately, which increases the process and makes it difficult to detect the composition; in addition, if the content of the grain boundary phase alloy (silicon nitride is a non-magnetic phase alloy) is not controlled accurately, it will affect the coercive force. cause negative impact

[0006] CN102237166A discloses a NdFeB permanent magnet material and a preparation method thereof, aiming at the complex process of preparing sintered NdFeB magnets by the double alloy method in the prior art, the difficulty in controlling the content of the grain boundary phase, and the difficulty in obtaining a high Curie temperature by the single alloy method And the problem of high coercive force, using the method of doping preparation, doping 0.02wt% - 3wt% nano-silicon carbide after the NdFeB alloy airflow milling, and then mixing the mixed particles, magnetic field compression molding and sintering Tempering to produce NdFeB magnets with high working temperature and coercive force

However, in this method, the content of dysprosium in the magnet is high, the production cost increases, the high temperature magnetic performance is improved, but the room temperature magnetic performance is greatly reduced

[0010] To sum up, the current methods to improve the coercive force and working temperature of NdFeB permanent magnet materials usually contain relatively high content of heavy rare earth dysprosium or terbium, scarce strategic metal cobalt, or use complex control and easy to produce adverse reactions. However, there are problems such as low room temperature magnetic properties, high raw material costs, or complicated processes.

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