中国物理B ›› 2018, Vol. 27 ›› Issue (11): 117504-117504.doi: 10.1088/1674-1056/27/11/117504

所属专题: TOPICAL REVIEW — Magnetism, magnetic materials, and interdisciplinary research

• TOPICAL REVIEW—Magnetism, magnetic materials, and interdisciplinary research • 上一篇    下一篇

Rare earth permanent magnets prepared by hot deformation process

Ren-Jie Chen(陈仁杰), Ze-Xuan Wang(王泽轩), Xu Tang(唐旭), Wen-Zong Yin(尹文宗), Chao-Xiang Jin(靳朝相), Jin-Yun Ju(剧锦云), Don Lee(李东), A-Ru Yan(闫阿儒)   

  1. 1 CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China;
    2 University of Dayton, Dayton, OH, USA
  • 收稿日期:2018-09-25 修回日期:2018-10-25 出版日期:2018-11-05 发布日期:2018-11-05
  • 通讯作者: Ren-Jie Chen, A-Ru Yan E-mail:chenrj@nimte.ac.cn;aruyan@nimte.ac.cn
  • 基金资助:

    Project supported by the National Key Research and Development Program of China (Grant No. 2016YFB0700902) and the National Natural Science Foundation of China (Grant Nos. 51671207, 51601207, and 51501213).

Rare earth permanent magnets prepared by hot deformation process

Ren-Jie Chen(陈仁杰)1, Ze-Xuan Wang(王泽轩)1, Xu Tang(唐旭)1, Wen-Zong Yin(尹文宗)1, Chao-Xiang Jin(靳朝相)1, Jin-Yun Ju(剧锦云)1, Don Lee(李东)2, A-Ru Yan(闫阿儒)1   

  1. 1 CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China;
    2 University of Dayton, Dayton, OH, USA
  • Received:2018-09-25 Revised:2018-10-25 Online:2018-11-05 Published:2018-11-05
  • Contact: Ren-Jie Chen, A-Ru Yan E-mail:chenrj@nimte.ac.cn;aruyan@nimte.ac.cn
  • Supported by:

    Project supported by the National Key Research and Development Program of China (Grant No. 2016YFB0700902) and the National Natural Science Foundation of China (Grant Nos. 51671207, 51601207, and 51501213).

摘要:

Hot deformation is one of the primary methods for fabricating anisotropic rare earth permanent magnets. Firstly, rapidly quenched powder flakes with a nanocrystal structure are condensed into fully dense isotropic precursors using the hot-pressing process. The prepared isotropic precursors are then hot-deformed to produce high-anisotropy uniaxial bulk rare earth permanent magnets and a highly textured structure is produced via this process. The resulting magnets possess many advantages such as near-net-shape, outstanding corrosion resistance, and ultrafine-grain structure. The influence of the preparation parameters utilized in the hot-pressing and deformation processes on the magnetic properties and microstructure of the permanent magnets are systemically summarized in this report. As a near-net-shape technique, the hot deformation process has notable advantages with regard to the production of irregular shapes, especially for radially oriented ring-shaped magnets with high length-diameter ratios or thin walls. The difficulties associated with the fabrication of crack-free, homogeneous, and non-decentered ring-shaped magnets are substantially resolved through an emphasis on mold design, adjustment of deformation parameters, and application of theoretical simulation. Considering the characteristics of hot-deformed magnets which include grain shape and size, anisotropic distribution of intergranular phases, etc., investigation and improvement of the mechanical and electric properties, in addition to thermal stability, with the objective of improving the application of hot-deformed magnets or ring-shaped magnets, is of practical significance.

关键词: hot deformation, Nd-Fe-B permanent magnets, high coercivity, nanocomposite, radially oriented Nd-Fe-B ring magnet

Abstract:

Hot deformation is one of the primary methods for fabricating anisotropic rare earth permanent magnets. Firstly, rapidly quenched powder flakes with a nanocrystal structure are condensed into fully dense isotropic precursors using the hot-pressing process. The prepared isotropic precursors are then hot-deformed to produce high-anisotropy uniaxial bulk rare earth permanent magnets and a highly textured structure is produced via this process. The resulting magnets possess many advantages such as near-net-shape, outstanding corrosion resistance, and ultrafine-grain structure. The influence of the preparation parameters utilized in the hot-pressing and deformation processes on the magnetic properties and microstructure of the permanent magnets are systemically summarized in this report. As a near-net-shape technique, the hot deformation process has notable advantages with regard to the production of irregular shapes, especially for radially oriented ring-shaped magnets with high length-diameter ratios or thin walls. The difficulties associated with the fabrication of crack-free, homogeneous, and non-decentered ring-shaped magnets are substantially resolved through an emphasis on mold design, adjustment of deformation parameters, and application of theoretical simulation. Considering the characteristics of hot-deformed magnets which include grain shape and size, anisotropic distribution of intergranular phases, etc., investigation and improvement of the mechanical and electric properties, in addition to thermal stability, with the objective of improving the application of hot-deformed magnets or ring-shaped magnets, is of practical significance.

Key words: hot deformation, Nd-Fe-B permanent magnets, high coercivity, nanocomposite, radially oriented Nd-Fe-B ring magnet

中图分类号:  (Fine-particle systems; nanocrystalline materials)

  • 75.50.Tt
75.50.Vv (High coercivity materials) 75.50.Ww (Permanent magnets) 75.60.Ej (Magnetization curves, hysteresis, Barkhausen and related effects)