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

doi:10.1088/1674-1056/24/1/017504

Abstract Fine-grained Nd_10.79Pr_2.8Al_0.4B_7.72Fe_78.29 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.

Keywords: NdFeB magnets grain refinement hot press pre-sintering

Received: 01 August 2014
Revised: 25 August 2014
Accepted manuscript online:

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

Fund: 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).

Corresponding Authors: Chen Ren-Jie, Yan A-Ru
E-mail: chenrj@nimte.ac.cn;aruyan@nimte.ac.cn

Cite this article:

Ju Jin-Yun (剧锦云), Tang Xu (唐旭), Chen Ren-Jie (陈仁杰), Wang Jin-Zhi (汪金芝), Yin Wen-Zong (尹文宗), Lee Don (李东), Yan A-Ru (闫阿儒) Fine-grained NdFeB magnets prepared by low temperature pre-sintering and subsequent hot pressing 2015 Chin. Phys. B 24 017504

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

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