Title:
METHOD FOR PREPARING HIGH-COERCIVITY SINTEREDND-FE-B AND PRODUCT OBTAINED THEREBY
Document Type and Number:
WIPO Patent Application WO/2016/086398
Kind Code:
A1
Abstract:
Disclosed is a method for preparing a high-coercivity sintered Nd-Fe-B, comprising: preparing a main phase alloy powder and a grain boundary phase alloy powder; uniformly mixing the prepared grain boundary phase alloy powder and main phase alloy powder in a protective medium protected by nitrogen gas or argon gas, the grain boundary phase alloy powder added being 0.1-10% by weight; orientation-compressing and cold-isostatic-pressing the mixed alloy powder; in a vacuum sintering furnace, sintering a compressed magnet block at 1000-1100˚C for 2-4 hours, and performing a primary tempering at 800-950˚C for 2-4 hours and a secondary tempering at 450-650˚C for 2-4 hours to obtain the sintered Nd-Fe-B. Also disclosed is a high-coercivity sintered Nd-Fe-B. The present invention reduces a wetting temperature between the grain boundary phase and the main phase via a low melting point auxiliary alloy, and extends wetting time, thus improving the utilization of heavy rare earths, and reducing the usage amount of the rare earths; and the preparation method has a simple process and low cost, thus facilitating large-scale production.
Inventors:
YAN MI (CN)
ZHANG YUJING (CN)
WANG XINHUA (CN)
JIN JIAYING (CN)
ZHANG YUJING (CN)
WANG XINHUA (CN)
JIN JIAYING (CN)
Application Number:
PCT/CN2014/093069
Publication Date:
June 09, 2016
Filing Date:
December 04, 2014
Export Citation:
Assignee:
UNIV ZHEJIANG (CN)
International Classes:
H01F1/057; H01F1/08
Foreign References:
| CN101615461A | 2009-12-30 | |||
| CN101364465A | 2009-02-11 | |||
| US5000800A | 1991-03-19 |
Attorney, Agent or Firm:
HANGZHOU TIANQIN INTELLECTUAL PROPERTY AGENCY CO., LTD (CN)
杭州天勤知识产权代理有限公司 (CN)
杭州天勤知识产权代理有限公司 (CN)
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