METHOD FOR PREPARING RARE-EARTH PERMANENT MAGNETIC MATERIALS - ZHEJIANG DONGYANG DMEGC RARE EARTH MAGNET CO LTD

Title:

METHOD FOR PREPARING RARE-EARTH PERMANENT MAGNETIC MATERIALS

Document Type and Number:

WIPO Patent Application WO/2018/040299

Kind Code:

A1

Abstract:

A method for preparing rare-earth permanent magnetic materials, comprising the following steps: selecting a sintered neodymium iron boron (NdFeB) blank, a waste NdFeB magnet or NdFeB scrap after washing and stoving, breaking same down into NdFeB powder; applying an oriented magnetic field to the NdFeB powder to turn the latter into a NdFeB green part; placing the NdFeB green part within the cavity of a pressure sintering mold, the pressure sintering mold being in a hermetically sealed space, under a vacuum or the protection of insert gas, heating and pressurizing to perform the pressure sintering, and then cooling and taking out; placing the pressure-sintered magnet within a vacuum furnace to perform heat treatment for secondary tempering, and obtaining a NdFeB magnet. The method has advantages of good magnetic powder flowability, high production efficiency, small product deformation and less crack; the oriented magnetic field is low, and a stable mass production of special oriented magnet such as a radiation ring can be realized; pressure sintering is performed by using the pressure sintering mold, the dimensions of the magnet are approximate to the dimensions of a final finished product, the material utilization and the magnetic property are high, and cost is low.

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Inventors:

HAO ZHONGBIN (CN)
HAN XIANGHUA (CN)
HONG QUNFENG (CN)
ZHANG XIAOFENG (CN)

Application Number:

PCT/CN2016/106318

Publication Date:

March 08, 2018

Filing Date:

November 18, 2016

Export Citation:

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Assignee:

ZHEJIANG DONGYANG DMEGC RARE EARTH MAGNET CO LTD (CN)

International Classes:

H01F1/057

Foreign References:

CN101901657A	2010-12-01
CN102024544A	2011-04-20
CN101877265A	2010-11-03
CN101572146A	2009-11-04
US20100321139A1	2010-12-23

Attorney, Agent or Firm:

HANGZHOU HANGCHENG PATENT ATTORNEY OFFICE CO., LTD (CN)

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