Granulation method of sintered NdFeB powder

Abstract

The invention discloses a granulation method of sintered neodymium iron boron powder materials. The granulation method comprises the following steps of producing sintered neodymium iron boron materials into fine powder materials, wherein the average particle size of the fine powder materials is 2 to 5 microns; adding the fine powder materials into a mold chamber; performing orientation on the fine powder materials through the magnetic field, wherein the magnetic field is larger than 0.8 teslas and the orientation time is larger than 2 seconds; performing compression forming on the fine powder materials to obtain a green body; performing granulation on the green body to obtain the sintered neodymium iron boron powder materials, wherein the average particle size of the sintered neodymium iron boron powder materials is 15 to 100 microns. According to the granulation method of the sintered neodymium iron boron powder materials, the orientation of the sintered neodymium iron boron powder materials is sufficient; the apparent density is high; the liquidity is good; the sintered neodymium iron boron powder materials can be applied to production of products which are thin in wall and high in filled height directly, regular large pieces of blanks do not need to be produced first, and accordingly the production cost is reduced.

Description

technical field [0001] The invention relates to a granulation method, in particular to a granulation method of sintered NdFeB powder. Background technique [0002] Sintered NdFeB permanent magnet materials are currently the most magnetic materials, widely used in electromagnetics, electroacoustics, magnetism, nuclear magnetism and electron accelerated luminescence and other disciplines, such as various motors, speakers, magnetic coupling devices, medical Equipment and devices such as imaging equipment and free electron oscillators. [0003] Sintered NdFeB permanent magnet materials are manufactured by powder metallurgy. The preparation process is generally: raw material preparation → smelting → casting → crushing and powder making → magnetic field orientation and pressing → sintering → aging → machining and surface Processing → detection. Magnetic field orientation and pressing is one of the key technologies for manufacturing high-performance sintered NdFeB permanent magne...

AI Technical Summary

Problems solved by technology

[0004] But as we all know, powders with an average particle size of 2-5 μm are dusty, have low bulk density and poor fluidity, and have little effect on products with large sizes, but for some products with thin walls and high filling height (height-to-diameter ratio greater than or equal to 4) The product is very difficult to form, not only difficult to fill, low efficiency, but also difficult to control the uniformity of the compact, the product has a large amount of deformation after sintering, is easy to crack, and its size also has certain limitations

In order to overcome the above problems and successfully manufacture the required products, people usually can only make relatively regular large blanks first, and then use processing technology to process the required small products, which leads to an increase in the processing allowance of the material and reduces the The yield rate of the material is increased, and the cost of the product is increased

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