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Coercivity, microstructure, and thermal stability of sintered Nd–Fe–B magnets by grain boundary diffusion with TbH3 nanoparticles

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Abstract

Grain boundary diffusion technique with TbH3 nanoparticles was applied to fabricate Tb-less sintered Nd–Fe–B permanent magnets with high coercivity. The magnetic properties and microstructure of magnets were systematically studied. The coercivity and remanence of grain boundary diffusion magnet are improved by 112 % and reduced by 26 % compared with those of the original magnet, respectively. Meanwhile, both the remanence temperature coefficient (α) and the coercivity temperature coefficient (β) of the magnets are improved after diffusion treatment. Microstructure shows that Tb element enriches in the surface region of Nd2Fe14B grains and is expected to exist as (Nd,Tb)2Fe14B phase. Thus, the magneto-crystalline anisotropy field of the magnet improves remarkably. As a result, the sintered Nd-Fe-B magnets by grain boundary diffusion with TbH3 nanoparticles exhibit enhanced coercivity.

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Acknowledgments

This study was financially supported by the National Natural Science Foundation of China (Nos. 51001002 and 51371002), the National High Technology Research and Development Program of China (No. 2012AA063201), the Key Program of Science and Technology Development Project of Beijing Municipal Education Commission (No. KZ201110005007), Jinghua Talents of Beijing University of Technology, Rixin Talents of Beijing University of Technology, the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions.

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  1. College of Materials Science and Engineering, Beijing University of Technology, Beijing, 100124, China

    Wei-Qiang Liu, Cheng Chang, Ming Yue, Jing-Shan Yang, Dong-Tao Zhang, Jiu-Xing Zhang & Yan-Qin Liu

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  1. Wei-Qiang Liu
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  2. Cheng Chang
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  3. Ming Yue
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  4. Jing-Shan Yang
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  5. Dong-Tao Zhang
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  7. Yan-Qin Liu
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Correspondence to Wei-Qiang Liu or Ming Yue.

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Liu, WQ., Chang, C., Yue, M. et al. Coercivity, microstructure, and thermal stability of sintered Nd–Fe–B magnets by grain boundary diffusion with TbH3 nanoparticles. Rare Met. 36, 718–722 (2017). https://doi.org/10.1007/s12598-014-0295-2

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  • DOI: https://doi.org/10.1007/s12598-014-0295-2

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