Preparation method of anti-corrosive neodymium iron boron magnet
A NdFeB, corrosion-resistant technology, used in magnetic objects, inductor/transformer/magnet manufacturing, magnetic materials, etc., can solve the problems of intergranular corrosion, poor corrosion resistance of sintered NdFeB magnets, and large electrode potential difference.
Active Publication Date: 2017-06-30
京磁材料科技股份有限公司
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Problems solved by technology
In addition, due to the large electrode potential difference between the main phase and the grain boundary phase, intergranular corrosion is prone to occur.
The poor corrosion resistance of sintered NdFeB magnets seriously limits its application in important fields
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[0086] The present invention will be further described in detail below in conjunction with the accompanying drawings, so that those skilled in the art can implement it with reference to the description.
[0087] It should be understood that terms such as "having", "comprising" and "including" as used herein do not entail the presence or addition of one or more other elements or combinations thereof.
[0088] The strong magnetism of sintered NdFeB magnets comes from Nd 2 Fe 14 Phase B. Nd 2 Fe 14 B has a tetragonal structure, and the unit cell space structure is as figure 1 shown. Sintered NdFeB is a polycrystalline composite material, mainly composed of Nd 2 Fe 14 B main phase, Nd-rich grain boundary phase, there may also be a small amount of B-rich phase, Nd 2 o 3 、Nd 2 Fe 17 or a-Fe soft magnetic phase; in addition, Nd may appear in the grain boundary region of the alloyed magnet 6 Fe 13 Cu, Nd 6 Fe 13 Ga, NdCu and other alloy phases. The Nd-rich phase is a n...
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Abstract
The invention provides a preparation method of an anti-corrosive neodymium iron boron magnet. The preparation method comprises the following steps: preparing the neodymium iron boron magnet sintered raw material as neodymium iron boron hydrogen blasting powder; performing the air-stream milling treatment on the prepared neodymium iron boron hydrogen blasting powder to obtain the magnetic powder, and preparing the neodymium iron boron magnet through the magnetic powder, wherein the oxygen content in the air-stream in the air-stream milling treatment is 800-900ppm, the particle size of the neodymium iron boron hydrogen blasting powder is 2.9-3.1 microns. By adjusting the existing mass production 35K process parameter, the oxygen content is improved and the powder size is reduced, an aim of obviously lowering the magnet weight loss is achieved, and magnetic mass loss is lowered to 1.77-2.04mg / cm<2> from 51.56mg / cm<2>. By exploring different sample preparing methods, the magnetic weight loss tends to 0mg / cm<2>.
Description
technical field [0001] The invention belongs to the field of neodymium-iron-boron magnets, and in particular relates to a preparation method of a corrosion-resistant neodymium-iron-boron magnet. Background technique [0002] NdFeB permanent magnet materials are divided into sintered and bonded permanent magnets according to the preparation method. The former accounts for about 85% of the total output, according to the dominant position. Sintered NdFeB is an energy storage device with high energy density, which can meet the requirements of high coercive force and high magnetic energy product, and is especially suitable for the preparation of high-performance, miniaturized and light-weight devices. Sintered NdFeB is widely used in military equipment, electroacoustic devices, motors, generators, computer hard disk drives (HDD), voice coil motors (VCM), human magnetic resonance imaging (MRI), microwave communication technology, controllers, instruments, magnetic In separation e...
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IPC IPC(8): H01F41/02H01F1/057B22F1/02B22F9/04C23C18/18C23C18/32
CPCH01F1/0573H01F1/0576H01F1/0577H01F41/0266C23C18/1844C23C18/32B22F9/04B22F2009/045B22F1/17
Inventor 赵媛媛杨晓霞
Owner 京磁材料科技股份有限公司