Structure and magnetic properties of bulk nanocrystalline Nd-Fe-B permanent magnets prepared by hot pressing and hot deformation

Structure and magnetic properties were studied for bulk nanocrystalline Nd-Fe-B permanent magnets that were prepared at 650 ℃ for 3 min under 300 MPa using the SPS-3.20-MK-V sintering machine and the hot pressed magnets were then submitted to hot deformation with height reduction of 50%, 60%, 70%, 8...

Full description

Saved in:
Bibliographic Details
Published inJournal of rare earths Vol. 31; no. 7; pp. 674 - 678
Main Author 宋杰 岳明 左建华 张子瑞 刘卫强 张东涛 张久兴 郭朝晖 李卫
Format Journal Article
LanguageEnglish
Published Elsevier B.V 01.07.2013
Subjects
Deformation
Ferrous alloys
hot deformation
hot pressing
Magnetic materials
Magnetic properties
Magnets
microstructure
nanocrystalline Nd-Fe-B magnets
Nd-Fe-B
Permanent magnets
Rare earth metals
rare earths
Reduction
块体
晶体结构
永磁
热变形磁体
磁学性质
磁铁
纳米
nanocrystalline Nd-Fe-B magnets
microstructure
magnetic properties
hot pressing
hot deformation
rare earths
Online AccessGet full text
ISSN1002-0721
2509-4963
DOI10.1016/S1002-0721(12)60341-X

Cover

More Information
Summary:Structure and magnetic properties were studied for bulk nanocrystalline Nd-Fe-B permanent magnets that were prepared at 650 ℃ for 3 min under 300 MPa using the SPS-3.20-MK-V sintering machine and the hot pressed magnets were then submitted to hot deformation with height reduction of 50%, 60%, 70%, 80%, and 85%. Effects of height reduction （HR） and deformation temperature on the structure and magnetic properties of the magnets were investigated. The crystal structure was evaluated by means of X-ray diffraction （XRD） and the microstructure was observed by transmission electron microscopy （TEM）. The magnetic properties of the magnets were investigated by vibrating sample magnetometer （VSM）. As the height reduction increased, the remanence （Br） of the magnets increased first, peaks at 1.3 T with HR=60%, then decreased again, and the coercivity （Hci） of the magnets decreased monotonically. On the other hand, as the deformation temperature increased, the Br of the magnets increased first, peaks at 1.36 T with HR=60%, then decreased again, and the H~i of the magnets decreased monotonically. Under optimal conditions, the hot deformed magnet possessed excellent magnetic properties as Brl.36 T, Hci=1143 kA/m, and （BH）max=370 kJ/m3, suggesting the good potential of the magnets in practical applications.
Bibliography:nanocrystalline Nd-Fe-B magnets; hot pressing; hot deformation; microstructure; magnetic properties; rare earths
11-2788/TF
SONG Jie , YUE Ming , ZUO Jianhua , ZHANG Zimi , LIU Weiqiang , ZHANG Dongtao , ZHANG Jiuxing , GUO Zhaohui , LI Wei （1. College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China; 2. Division of Functional Materials, Central Iron and Steel Research Institute, Beijing 100081, China）
Structure and magnetic properties were studied for bulk nanocrystalline Nd-Fe-B permanent magnets that were prepared at 650 ℃ for 3 min under 300 MPa using the SPS-3.20-MK-V sintering machine and the hot pressed magnets were then submitted to hot deformation with height reduction of 50%, 60%, 70%, 80%, and 85%. Effects of height reduction （HR） and deformation temperature on the structure and magnetic properties of the magnets were investigated. The crystal structure was evaluated by means of X-ray diffraction （XRD） and the microstructure was observed by transmission electron microscopy （TEM）. The magnetic properties of the magnets were investigated by vibrating sample magnetometer （VSM）. As the height reduction increased, the remanence （Br） of the magnets increased first, peaks at 1.3 T with HR=60%, then decreased again, and the coercivity （Hci） of the magnets decreased monotonically. On the other hand, as the deformation temperature increased, the Br of the magnets increased first, peaks at 1.36 T with HR=60%, then decreased again, and the H~i of the magnets decreased monotonically. Under optimal conditions, the hot deformed magnet possessed excellent magnetic properties as Brl.36 T, Hci=1143 kA/m, and （BH）max=370 kJ/m3, suggesting the good potential of the magnets in practical applications.
ObjectType-Article-2
SourceType-Scholarly Journals-1
ObjectType-Feature-1
content type line 23
ObjectType-Article-1
ObjectType-Feature-2
ISSN:1002-0721
2509-4963
DOI:10.1016/S1002-0721(12)60341-X