Tempering technology for NdFeB magnet

Abstract

The invention provides a tempering technology for an NdFeB magnet. The tempering technology comprises steps as follows: firstly, under the condition of vacuum or protective gas, a sintered NdFeB magnet blank is subjected to primary heating and primary heat preservation, and a primary tempered intermediate is obtained after cooling; then, the primary tempered intermediate obtained in the step is tempered N times, and the NdFeB magnet is obtained; each tempering process is as follows: heating is performed firstly, cooling is performed, heat preservation is performed, and cooling is performed finally; the heat preservation temperature is T, and heat preservation temperatures of the tempering processes decrease sequentially; n is a natural number larger than or equal to 1. The technology starts from the tempering processes during preparation of the magnet, a technology of multistage tempering heat treatment is adopted, that is, a method adopting three-stage tempering after two-stage tempering is adopted, a multistage tempering method adopting four-stage tempering after two-stage tempering and three-stage tempering can be adopted, the coercivity can be effectively improved, and the density and square degree of the magnet can be improved.

Description

technical field [0001] The invention belongs to the technical field of magnet preparation, and in particular relates to a tempering process of an NdFeB magnet. Background technique [0002] A magnet is a substance that can generate a magnetic field and has the property of attracting ferromagnetic substances such as iron, nickel, cobalt and other metals. Magnets are generally divided into permanent magnets and soft magnets. Most of the materials used as magnetizers and electromagnets are soft magnets, and their polarity changes with the polarity of the applied magnetic field; permanent magnets are hard magnets, which can maintain their magnetic properties for a long time. , It is not easy to lose magnetization, and it is not easy to be magnetized. Therefore, whether in industrial production or in daily life, hard magnets are one of the most commonly used strong materials. [0003] Hard magnets can be divided into natural magnets and artificial magnets. Artificial magnets me...

AI Technical Summary

Problems solved by technology

With the increasing demand for applications, many technologies to improve the performance of sintered NdFeB have been proposed. Although they have been improved accordingly, they still cannot meet the requirements. In recent years, the research on the addition of rare earth elements has become a hot spot.

However, when rare earth elements, especially multiple rare earth elements, are added at the same time, the magnetic properties of the prepared NdFeB magnets cannot be maximized.

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