Preparation method of radiation-oriented sintered neodymium iron boron magnet ring

A radiation orientation, NdFeB technology, applied in the manufacture of inductors/transformers/magnets, magnetic materials, magnetic objects, etc., can solve the problems of cracking, deformation, uneven shrinkage, etc., to improve fluidity, reduce cracking rate, cracking rate drop effect

Inactive Publication Date: 2018-03-06
NINGBO KETIAN MAGNET
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Problems solved by technology

[0003] The present invention provides a method for effectively solving the problem of deformation or cracking caused by uneven shrinkage during the sintering process of radiation-oriented NdFeB magnetic rings in view of the above-mentioned technical status.

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  • Preparation method of radiation-oriented sintered neodymium iron boron magnet ring

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Embodiment 1

[0019] 1) Place the raw materials prepared in proportion into a vacuum quick-setting furnace for conventional smelting to obtain a cast sheet with a thickness of 0.3mm;

[0020] 2) Absorb the above-mentioned casting sheet at room temperature, and after the hydrogen absorption is saturated, dehydrogenate under vacuum at 550°C, and cool to room temperature after the dehydrogenation is completed, to obtain a coarse powder with a particle size of 300 μm;

[0021] 3) Add 0.15ml of antioxidant and 0.15ml of lubricant per kilogram of powder, dilute the antioxidant and lubricant with gasoline, the volume ratio of agent to gasoline is 1:1, and stir for 100 minutes;

[0022] 4) Put the uniformly stirred coarse powder into the jet mill, and under the protection of nitrogen, obtain a powder with a particle size of 20 μm;

[0023] 5) Add 0.5ml of antioxidant and 0.5ml of lubricant per kilogram of powder, dilute the antioxidant and lubricant with gasoline, the volume ratio of agent to gasol...

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Abstract

The invention provides a method for preparing a radiation orientation sintered NdFeB magnetic ring, which specifically includes smelting, hydrogen crushing, jet milling, radiation orientation molding and sintering. During the powder making process, through two jet mills and two additions of lubricants, the fluidity of the powder is improved, the powder is fully oriented along the radial direction in the magnetic field, and the density of the green compact becomes uniform in the axial and radial directions , greatly improve the roundness of the magnetic ring and the uniformity of the magnetic surface, and at the same time, the method of slow heating and cooling is adopted during the sintering process to reduce the internal stress caused by uneven cooling or heating, and the cracking rate of the magnetic ring sintering is greatly reduced.

Description

technical field [0001] The invention relates to a preparation method of an NdFeB permanent magnet material, in particular to a preparation method of a sintered NdFeB radiation orientation magnetic ring. Background technique [0002] Radiation-oriented ring-shaped sintered NdFeB magnets are more and more widely used in motors. They have the characteristics of no jumping in operation, stable output signals, and high speed. Because the ring magnet has a large specific surface area, and the ring magnet has the characteristics of a large aspect ratio and a thin wall, the magnet is prone to cracking during the molding and sintering process. In order to reduce cracking, it is necessary to improve the fluidity of the powder, so that the density and orientation of the compact are uniform in the axial and 360-degree radial directions. Patent No. 96190684.7 granulates magnetic powder under magnetic field orientation, and then disintegrates. This method is difficult to fully orient the...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F1/057H01F1/08H01F41/02B22F9/04B22F3/02B22F3/10
CPCH01F1/0573B22F3/02B22F3/1007B22F9/04B22F2003/023B22F2009/044H01F1/0575H01F41/0246
Inventor 严长江王育平徐峰
Owner NINGBO KETIAN MAGNET
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