A method and additive for reducing oxygen content of sintered NdFeB material

An additive, NdFeB technology, applied in the direction of magnetic materials, inductor/transformer/magnet manufacturing, magnetic objects, etc., can solve problems such as cracking, magnet performance degradation, and easy agglomeration
CN110444359BActive Publication Date: 2021-09-14ZHEJIANG DONGYANG DMEGC RARE EARTH MAGNET CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
ZHEJIANG DONGYANG DMEGC RARE EARTH MAGNET CO LTD
Publication Date
2021-09-14

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Abstract

The invention relates to the technical field of permanent magnet materials, and discloses a method and additives for reducing the oxygen content of sintered NdFeB materials. The method of the present invention adopts the pre-grinding and post-grinding two-step method to carry out anti-oxidation protection to the magnetic powder, and the pre-milling and post-grinding additives adopt different formulations (Type I and Type II), wherein the Type I additives include BTA, 200# solvent oil , isopropanol and cyclohexanone; Type II additives include stearate and 120# solvent oil, oleic acid amide, terpineol, petroleum ether and stadis (R) 450. In the present invention, the additive is added to the NdFeB powder in the form of continuous spraying, and the particle surface of the NdFeB powder is evenly coated, which improves the anti-oxidation effect of the NdFeB powder. The chain segment of the type I additive is slightly longer, It is convenient to cover the new section produced by jet milling; the chain segment of type II additive is slightly short and contains lubricant and polar group components, which can weaken the static magnetic effect between powder particles and reduce the agglomeration between powder particles, which is beneficial to improve degree of orientation.
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Description

Technical field

[0001] The present invention relates to the technical field of permanent magnet material, particularly to a method and an additive for reducing the oxygen content of the sintered NdFeB material. Background technique

[0002] NdFeB (NdFeB) permanent magnet materials are mainly iron, boron and some of the added metal such as Co, Cu, Al, Ga prepared from rare earth metal elements such as praseodymium, neodymium formed by a powder metallurgy process. NdFeB invention since, because of its high energy product, high coercivity, and light weight characteristics of the magnetic device to efficient, compact, lightweight direction. However, in the manufacturing process of sintered NdFeB material remaining in the following problems: First, the NdFeB powder needs nitrogen, stored or exposed to the air, the transfer is easily oxidized, damp, seriously affect the magnetic properties; Second when pressing the alignment between the NdFeB powder particles easily agglomerate due to ...

Claims

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