A kind of neodymium iron boron magnet and preparation method thereof

Abstract

The invention provides a neodymium iron boron magnet, which comprises: Pr-Nd: 29% to 33%, B: 0.97% to 1.5%, Dy: 0.4% to 0.6%, Al: 0.2% to 0.8%. , Co: 0.6% to 0.8%, Cu: 0.01% to 0.5%, Zr: 0.01% to 0.2%, and the balance is Fe. The invention also discloses a preparation method of a neodymium-iron-boron magnet. First, under vacuum conditions, Pr-Nd alloy, Zr-Fe alloy, B-Fe alloy, Dy-Fe alloy, aluminum, cobalt, copper and iron are melted The NdFeB ingot is prepared, and then the NdFeB ingot is pulverized to obtain NdFeB powder, and finally the NdFeB powder is sintered to obtain the NdFeB magnet. The neodymium-iron-boron magnet prepared by the method provided by the invention has finer magnet grain size and higher magnet stability.

Description

technical field [0001] The invention belongs to the technical field of magnet preparation, and in particular relates to an NdFeB magnet and a preparation method thereof. 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 ...

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Problems solved by technology

[0005] At present, the sintering method is often used in the industry to produce NdFeB magnets. Most of the sintering furnaces for sintered NdFeB magnets are heated by thermal radiation. However, due to the limitation of the sintering process, it is easy to cause excessive sintering of the magnets and produce grains. Abnormal growth, lower magnet coercive force, or insufficient sintering of the central magnet occurs

In the prior art, the patent CN10104187A discloses a preparation process and application of a zirconium hydrogen grain growth inhibitor, which first hydrogenates zirconium into ZrH in a hydrogen furnace X , and then use the zirconium hydrogen grain growth inhibitor airflow to grind it into ultrafine powder with a particle size of less than 2 μm, which can inhibit the abnormal growth of grains. The process is complicated, which is not conducive to industrial production

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