Machining method of neodymium iron boron powder

Abstract

The invention discloses a machining method of neodymium iron boron powder. The machining method of the neodymium iron boron powder comprises the following steps that a, pretreatment is conducted, oxide powder, coarse particles, dust, screws, rubber bands and other impurities in the neodymium iron boron powder are removed through a neodymium iron boron powder screening mechanism; b, forming and orientation is conducted, the powder screened in the step a is pressed into compacts with a certain shape and size, and meanwhile, the grain orientation degree obtained in a magnetic field orientation iskept as much as possible; c, package stripping is conducted, packaging of products compression molded in the step b is disassembled in a glove box; and d, sintering is conducted, the powder in the step c is put in a high-vacuum space, and the powder is acted at a high temperature, the solid particles inside the powder are mutually bonded in a keyed mode, crystal gaps (namely air holes ) and grainboundaries are gradually reduced, the total volume is enabled to be reduced, and the density is increased. According to the machining method, through a first conveying belt made of ferromagnetic materials, the neodymium iron boron powder can attract the first conveying belt, so that the neodymium iron boron powder can be screened, the screening effect is good, and the screening is thorough.

Description

technical field [0001] The invention belongs to the field of NdFeB permanent magnets, in particular to a NdFeB powder processing method. Background technique [0002] NdFeB magnets can be divided into bonded NdFeB magnets and sintered NdFeB magnets. Bonding is actually injection molding, while sintering is vacuumized and formed by high temperature heating. NdFeB magnets have the most Permanent magnets with strong magnetic force (the magnetism is second only to holmium magnets at absolute zero, but the magnetism is far stronger than all known permanent magnets at room temperature), and the powder needs to be screened when processing NdFeB permanent magnets. In order to obtain a magnet with good performance, once foreign matter such as oxidized powder, coarse particles, dust, screws, rubber bands and other impurities are mixed into the NdFeB powder for pressing, these impurities will be loosely combined with the surrounding alloy structure during sintering. This area is prone...

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Problems solved by technology

[0002] NdFeB magnets can be divided into bonded NdFeB magnets and sintered NdFeB magnets. Bonding is actually injection molding, while sintering is vacuumized and formed by high temperature heating. NdFeB magnets have the most Permanent magnets with strong magnetic force (the magnetism is second only to holmium magnets at absolute zero, but the magnetism is far stronger than all known permanent magnets at room temperature), and the powder needs to be screened when processing NdFeB permanent magnets. In order to obtain a magnet with good performance, once foreign matter such as oxidized powder, coarse particles, dust, screws, rubber bands and other impurities are mixed into the NdFeB powder for pressing, these impurities will be loosely combined with the surrounding alloy structure during sintering. This area is prone to trachoma, which can lead to the scrapping of large quantities of products

[0003] Most of the existing screening is carried out by means of vibrating sieve. During the screening process, because the magnetic powder itself has a certain degree of magnetism, it is easy to combine with each other to change the size, which has a great impact on the screening and is not conducive to the realization of the screening process. , leading to the waste of NdFeB powder, and the dust screening effect is poor, and the NdFeB powder after screening is mixed with more impurities

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