Coercivity improvement of hot-deformed Nd-Fe-B magnets by stress-induced Pr-Cu eutectic diffusion

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	Coercivity improvement of hot-deformed Nd-Fe-B magnets by stress-induced Pr-Cu eutectic diffusion
	Yan, Aru; Lee, Don; Yin, Wenzong; Tang, Xu; Chen, Renjie; Ju, Jinyun; Wang, Jinzhi; Zhang, Jijun; Wang, Zexuan
刊名	ACTA MATERIALIA
	2018
卷号	156 页码:136-145
关键词	Grain-boundary Diffusion Permanent-magnets Sintered Magnets Size Dependence Rich Phase Microstructure Deformation Alloys Magnetization Enhancement
英文摘要	Low-melting eutectic diffusion has emerged as a practical approach to enhance the coercivity of hot deformed Nd-Fe-B magnets. Herein, we report a high-efficient stress-induced eutectic diffusion method to develop high-coercivity hot-deformed Nd-Fe-B magnets. In this method, fast Pr-Cu eutectic diffusion is accomplished with the hot-pressed and hot-deformed processes simultaneously. The coercivity of diffusion-processed magnets is substantially increased by about 33% with a slight remanence loss. The applied stress effectively controls the distribution of Pr-Cu eutectic and relieves the remanence loss. Microstructure analysis confirms that the Pr-Cu concentration gradient constructed in hot-pressed precursors effectively suppresses the near-surface grain growth during the hot-deformation process and reduces the lateral/longitudinal ratio of platelet-shaped grains. The formation of thick and continuous Pr-rich grain boundaries weakens the exchange coupling between neighboring grains, offering more "pinning" sites for domain wall displacement. Partially Pr-substitution improves the locally magnetically "hardening" of 2:14:1 main phases. The optimized structural and magnetic characterizations hinder the nucleation and propagation of reversed magnetic domains at low magnetic fields, which is beneficial to coercivity enhancement. These findings clarify the characteristics of the stress-induced diffusion method and give a new insight into the structural modulation for Nd-Fe-B materials. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
学科主题	Science & Technology - Other Topics ; Materials Science
语种	英语
公开日期	2018-12-04
内容类型	期刊论文
源URL	[http://ir.nimte.ac.cn/handle/174433/17225]
专题	2018专题
推荐引用方式 GB/T 7714	Yan, Aru,Lee, Don,Yin, Wenzong,et al. Coercivity improvement of hot-deformed Nd-Fe-B magnets by stress-induced Pr-Cu eutectic diffusion[J]. ACTA MATERIALIA,2018,156:136-145.
APA	Yan, Aru.,Lee, Don.,Yin, Wenzong.,Tang, Xu.,Chen, Renjie.,...&Wang, Zexuan.(2018).Coercivity improvement of hot-deformed Nd-Fe-B magnets by stress-induced Pr-Cu eutectic diffusion.ACTA MATERIALIA,156,136-145.
MLA	Yan, Aru,et al."Coercivity improvement of hot-deformed Nd-Fe-B magnets by stress-induced Pr-Cu eutectic diffusion".ACTA MATERIALIA 156(2018):136-145.