Coercivity enhancement in Dy-free sintered Nd-Fe-B magnets by effective structure optimization of grain boundaries

被引：43

作者：

Ding, Guangfei ^{[1
,2
]}

Guo, Shuai ^{[1
]}

Chen, Ling ^{[1
]}

Di, Jinghui ^{[1
]}

Song, Jie ^{[1
]}

Chen, Renjie ^{[1
]}

Lee, Don ^{[3
]}

Yan, Aru ^{[1
]}

机构：

[1] Chinese Acad Sci, Key Lab Magnet Mat & Devices, Ningbo Inst Mat Technol & Engn, Ningbo 315201, Zhejiang, Peoples R China

[2] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

[3] Univ Dayton, Dayton, OH 45469 USA

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 2018年 / 735卷

基金：

中国国家自然科学基金;

关键词：

Nd-Fe-B; Sintered magnet; Coercivity; Grain boundary; PERMANENT-MAGNETS; SIZE DEPENDENCE; MICROSTRUCTURE; PHASE; DIFFUSION; DECREASE; ALLOY; FORCE;

D O I：

10.1016/j.jallcom.2017.11.115

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

In this study, we presented an effective approach for the substantial coercivity enhancement of Dy-free sintered Nd-Fe-B magnets with Ga-doping. The coercivity was substantially enhanced from 10.1 kOe to 19.8 kOe by effective microstructure optimization and phase constitution regulation in antecedent alloys. A good isolation of 2:14:1 grains by Nd-rich intergranular phase is obtained in final magnets accompanying with the formation of intermetallic Nd6Fe13Ga phase. However, when dehydrogenating above 500 degrees C, masses of preformed Nd6Fe13Ga phases are detected in the initial strip casting alloys and the homologous magnet suffers an unanticipated degradation of coercivity. Magnetic domain observation and thermal magnetic analysis imply a pronounced difference in the magnetism of grain boundary (GB) phases, which closely associated with the composition homogeneity of Nd-rich phases in antecedent alloys. The mechanism of the coercivity variation in the sintered magnets with different GBs magnetism is discussed based on magnetic behavior analysis. (C) 2017 Elsevier B.V. All rights reserved.

引用

页码：795 / 801

页数：7