Partial pressure sintering method for sintering neodymium-iron-boron magnet

Abstract

The invention relates to a partial pressure sintering method for sintering a neodymium-iron-boron magnet. Certain inert gases Ar are filled into various deflation sections in the sintering process, the pressure of the Ar gases inside a furnace is regulated according to blank deflation velocity and vacuum pump system exhaust velocity through vacuum degree control, so that heating sintering is carried out by uniformly deflating under different partial pressures of the Ar gases, and negative pressure is still kept. The partial pressure sintering method disclosed by the invention ensures the consistency and uniformity of magnetic property and saves the sintering time.

Description

technical field [0001] The invention relates to a sintering method of a sintered NdFeB magnet. technical background [0002] Sintered NdFeB magnets have excellent magnetic properties at room temperature and are used in a wide range of fields, including electronic computers, motors and wind generators, nuclear magnetic resonance imaging devices, audio equipment, precision instruments, mineral processing, automation, aerospace and other aspects. With the application and development of high-tech fields, the requirements for the consistency of NdFeB magnets are getting higher and higher. Therefore, it is of great practical significance to develop high-consistency NdFeB magnets. Sintered NdFeB permanent magnet materials are basically used in vacuum sintering furnaces. The sintering process is carried out in a vacuum, and the heating is conducted in the form of heat radiation. Consistency is poor. [0003] Generally, there are three outgassing peaks in the process of sintering...

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Problems solved by technology

[0005] 2. The temperature range is 500-600°C. In the medium temperature pre-burning stage, the hydrogen remaining in the hydrogen scrap is mainly removed. During this process, there is more gas release, and the gas pressure inside the blank is higher than the pressure in the external furnace, so the gas release speed is faster. Fast, easy to cause micro-cracks, internal cracks and other phenomena in the blank

This kind of conventional vacuum sintering atmosphere is not good, it is easy to cause oxidation of the blank; and the uniformity of the sintering temperature is also poor, resulting in poor consistency of the magnetic properties of the blank; in addition, the entire sintering process is time-consuming and energy-consuming

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