Neodymium iron boron permanent magnet material preparation method

Abstract

The invention provides a neodymium iron boron permanent magnet material preparation method. Aluminum hydride is deposited on a neodymium iron boron magnet green body, the aluminum hydride releases reducing hydrogen during heating, oxidized heavy rare earth can be reduced at a high temperature, and grain boundary penetration effects can thus be improved. Aluminum is a low-melting-point metal, whenthe neodymium iron boron magnet is heated at a first sage, at a low temperature, on one hand, oil left on the surface of the neodymium iron boron green body in an isostatic pressing step is removed, and on the other hand, the low-melting-point aluminum is promoted to repair the surface grain boundary of the magnet. Dysprosium-iron alloy is then induced through second-stage heating to be quickly diffused with the well-repaired grain boundary low-melting point channel, the diffusion speed and the depth are enhanced, and the magnet can be completely dehydrogenated. Finally, through sintering, tempering and aging treatment, the neodymium iron boron permanent magnet material is obtained. The prepared neodymium iron boron permanent magnet material has the advantages of good uniformity, good consistency, deep diffusion of heavy rare earth, and the permanent magnet material performance is improved.

Description

technical field [0001] The invention belongs to the technical field of rare earth permanent magnet materials, and in particular relates to a preparation method of NdFeB permanent magnet materials. Background technique [0002] Since NdFeB permanent magnet materials came out in 1983, they have been widely used in various fields because of their excellent magnetism. In recent years, the demand for wind power generation, hybrid vehicles and electric vehicles has increased sharply. The coercive force and temperature stability of the material are required to be high, and it is required to be able to work above 200 °C. The traditional method increases the coercive force of the magnet through the alloying of Dy and Tb elements, but the heavy rare earth elements Dy, Tb, etc. are ferrimagnetically coupled with Fe atoms, which will lead to a decrease in the remanence and maximum energy product of the magnet, and The reserves of heavy rare earth elements are low and the cost is high. ...

AI Technical Summary

Problems solved by technology

The traditional method increases the coercive force of the magnet through the alloying of Dy and Tb elements, but the heavy rare earth elements Dy, Tb, etc. are ferrimagnetically coupled with Fe atoms, which will lead to a decrease in the remanence and maximum energy product of the magnet, and Heavy rare earth elements have low reserves and high cost

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