Neodymium-iron-boron magnet manufacturing process

Abstract

The invention discloses a neodymium-iron-boron magnet manufacturing process. The neodymium-iron-boron magnet manufacturing process comprises the following steps that a, smelting:, loading is performedfirstly and then vacuumizing to be less than 1 Pa is carried out, the low-power heating is started, heating while air extracting is performed, the moisture of the gas in an adsorption state is gradually de-absorbed and extracted along with temperature rise until the furnace burden is generally dark and red, a valve is closed and argon is injected, and power-increasing temperature rise is carriedout until the furnace burden is completely molten, five minutes of refining is carried out, the power is reduced after refining is completed and pouring is carried out, and then cooling is carried outafter pouring is finished; b, powder preparing: the neodymium-iron-boron particles are put into a jet mill to perform high-speed collision, so that the particles are subjected to high-speed collisionto form powder, the formed powder is collected and put into a screening machine to be screened, and impurities in the magnetic powder are removed; c, forming; d, sintering; e, machining, wherein theneodymium-iron-boron magnet obtained after sintering is a blank, and further machining is required to obtain products with different dimensions, sizes and shapes; f, surface treatment; and g, finishedproduct inspection and packaging are carried out.

Description

technical field [0001] The invention belongs to the technical field of NdFeB magnet processing, and in particular relates to a NdFeB magnet manufacturing process. Background technique [0002] Neodymium magnet (Neodymium magnet), also known as NdFeB magnet (NdFeB magnet), is a tetragonal crystal formed by neodymium, iron, and boron (Nd2Fe14B). In 1982, Masato Sagawa of Sumitomo Special Metals discovered neodymium magnets. The magnetic energy product (BHmax) of this magnet is greater than that of the samarium cobalt magnet, and it was the material with the largest magnetic energy product in the world at that time. Later, Sumitomo Special Metals successfully developed the powder metallurgy process, and General Motors successfully developed the melt-spinning process, which was able to prepare NdFeB magnets. This kind of magnet is the second most magnetic permanent magnet after the absolute zero holmium magnet, and it is also the most commonly used rare earth magnet. NdFeB ma...

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Problems solved by technology

[0003] The manufacture of NdFeB magnets needs to go through the process of powder making. After the magnetic powder is manufactured, there are some impurities inside. It is necessary to remove the impurities in the magnetic powder to improve the performance of the magnetic powder. The existing method of removing impurities from the magnetic powder is usually to put the magnetic powder into the vibrating The pairs on the sieve will be shaken off. Because the magnetic powder itself is magnetic, the magnetic powder will stick to each other and affect the filtering effect of the magnetic powder. Large pieces of magnetic powder will easily block the sieve holes and affect the service life of the vibrating screen.

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