›› 2015, Vol. 24 ›› Issue (1): 17504-017504.doi: 10.1088/1674-1056/24/1/017504

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Fine-grained NdFeB magnets prepared by low temperature pre-sintering and subsequent hot pressing

剧锦云a b, 唐旭a b, 陈仁杰a b, 汪金芝c, 尹文宗a b, 李东a b, 闫阿儒a b   

  1. a Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China;
    b Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China;
    c Ningbo University of Technology, Ningbo 315201, China
  • 收稿日期:2014-08-01 修回日期:2014-08-25 出版日期:2015-01-05 发布日期:2015-01-05
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 51101167), the National Science and Technology Major Project, China (Grant No. 2012ZX02702006-005), the Local Cooperation Project of Chinese Academy of Sciences (Grant No. DBSH-2011-013), the Natural Science Foundation of Zhejiang Province, China (Grant No. LQ14E010007), and the Natural Science Foundation of Ningbo, China (Grant No. 2014A610161).

Fine-grained NdFeB magnets prepared by low temperature pre-sintering and subsequent hot pressing

Ju Jin-Yun (剧锦云)a b, Tang Xu (唐旭)a b, Chen Ren-Jie (陈仁杰)a b, Wang Jin-Zhi (汪金芝)c, Yin Wen-Zong (尹文宗)a b, Lee Don (李东)a b, Yan A-Ru (闫阿儒)a b   

  1. a Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China;
    b Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China;
    c Ningbo University of Technology, Ningbo 315201, China
  • Received:2014-08-01 Revised:2014-08-25 Online:2015-01-05 Published:2015-01-05
  • Contact: Chen Ren-Jie, Yan A-Ru E-mail:chenrj@nimte.ac.cn;aruyan@nimte.ac.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 51101167), the National Science and Technology Major Project, China (Grant No. 2012ZX02702006-005), the Local Cooperation Project of Chinese Academy of Sciences (Grant No. DBSH-2011-013), the Natural Science Foundation of Zhejiang Province, China (Grant No. LQ14E010007), and the Natural Science Foundation of Ningbo, China (Grant No. 2014A610161).

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摘要： Fine-grained Nd10.79Pr2.8Al0.4B7.72Fe78.29 magnets were prepared by low temperature pre-sintering and subsequent hot pressing. The grain size of the magnets is just about 1-3μm because the low sintering temperature results in no grain growth. The orientation degree, microstructure, and magnetic properties were studied. Some grains' easy axes deviate from the orientation direction, possibly due to grain rotation during the hot pressing. By subsequent annealing, the magnetic properties were significantly enhanced. Especially, the squareness of the demagnetization curve was improved greatly. The enhancement of coercivity by annealing can be explained by an improvement of both grain boundaries and magnetic isolation, which decouples the exchange interaction between neighboring grains.

关键词: NdFeB magnets, grain refinement, hot press, pre-sintering

Abstract: Fine-grained Nd10.79Pr2.8Al0.4B7.72Fe78.29 magnets were prepared by low temperature pre-sintering and subsequent hot pressing. The grain size of the magnets is just about 1-3μm because the low sintering temperature results in no grain growth. The orientation degree, microstructure, and magnetic properties were studied. Some grains' easy axes deviate from the orientation direction, possibly due to grain rotation during the hot pressing. By subsequent annealing, the magnetic properties were significantly enhanced. Especially, the squareness of the demagnetization curve was improved greatly. The enhancement of coercivity by annealing can be explained by an improvement of both grain boundaries and magnetic isolation, which decouples the exchange interaction between neighboring grains.

Key words: NdFeB magnets, grain refinement, hot press, pre-sintering

中图分类号:  (Permanent magnets)

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