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

被引：46
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
收藏
页码：795 / 801
页数：7
相关论文
共 36 条
[1]   HYDROGEN-INDUCED METAMAGNETISM IN R(6)FE(13)X COMPOUNDS [J].
COEY, JMD ;
QI, QN ;
KNOCH, KG ;
LEITHEJASPER, A ;
ROGL, P .
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 1994, 129 (01) :87-97
[2]   Microstructure optimization to achieve high coercivity in anisotropic Nd-Fe-B thin films [J].
Cui, W. B. ;
Takahashi, Y. K. ;
Hono, K. .
ACTA MATERIALIA, 2011, 59 (20) :7768-7775
[3]   Enhanced Thermal Stability of Nd-Fe-B Sintered Magnets by Intergranular Doping Y72Co28 Alloys [J].
Ding, Guangfei ;
Guo, Shuai ;
Cai, Lingwen ;
Chen, Ling ;
Yan, Changjiang ;
Lee, Don ;
Yan, Aru .
IEEE TRANSACTIONS ON MAGNETICS, 2015, 51 (08)
[4]   THE INFLUENCE OF GA-SUBSTITUTION ON THE COERCIVITY OF ND-(FE,CO)-B SINTERED PERMANENT-MAGNETS [J].
FIDLER, J ;
GROISS, C ;
TOKUNAGA, M .
IEEE TRANSACTIONS ON MAGNETICS, 1990, 26 (05) :1948-1950
[5]   Grain-size dependence of remanence and coercive field of isotropic nanocrystalline composite permanent magnets [J].
Fischer, R ;
Schrefl, T ;
Kronmuller, H ;
Fidler, J .
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 1996, 153 (1-2) :35-49
[6]   Magnetic and microstructural properties of nanocrystalline exchange coupled PrFeB permanent magnets [J].
Goll, D ;
Seeger, M ;
Kronmuller, H .
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 1998, 185 (01) :49-60
[7]   REPLACEMENT OF ND BY AN INTERMETALLIC PHASE IN THE INTERGRANULAR REGION OF FE-ND-B SINTERED MAGNETS [J].
GRIEB, B ;
PITHAN, C ;
HENIG, ET ;
PETZOW, G .
JOURNAL OF APPLIED PHYSICS, 1991, 70 (10) :6354-6356
[8]   Magnetic Materials and Devices for the 21st Century: Stronger, Lighter, and More Energy Efficient [J].
Gutfleisch, Oliver ;
Willard, Matthew A. ;
Bruck, Ekkes ;
Chen, Christina H. ;
Sankar, S. G. ;
Liu, J. Ping .
ADVANCED MATERIALS, 2011, 23 (07) :821-842
[9]   Strategy for high-coercivity Nd-Fe-B magnets [J].
Hono, K. ;
Sepehri-Amin, H. .
SCRIPTA MATERIALIA, 2012, 67 (06) :530-535
[10]   Impact of different Nd-rich crystal-phases on the coercivity of Nd-Fe-B grain ensembles [J].
Hrkac, G. ;
Woodcock, T. G. ;
Butler, K. T. ;
Saharan, L. ;
Bryan, M. T. ;
Schrefl, T. ;
Gutfleisch, O. .
SCRIPTA MATERIALIA, 2014, 70 :35-38
1234