The mechanism of coercivity enhancement by the grain boundary diffusion process of Nd-Fe-B sintered magnets
The mechanism of coercivity enhancement by the grain boundary diffusion process of Nd-Fe-B sintered magnets
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DOI：
10.1016/j.actamat.2012.12.018
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发表时间：
2013-04-01
期刊：
影响因子：
9.4
通讯作者：
Hono, K.
中科院分区：
文献类型：
--
作者：
Sepehri-Amin, H.;Ohkubo, T.;Hono, K.
我们讨论了晶界扩散过程（GBDP）使用Dy蒸汽的基础上详细的微观结构表征的矫顽力增强的机制。扫描电子显微镜和电子探针分析表明，立方试样中，（Nd，Dy）（2）Fe 14 B壳层形成于Nd2 Fe 14 B晶粒的外围区域，其厚度从表面向中心逐渐减小。原子探针断层扫描表明，晶界处的Dy含量与（Nd，Dy）（2）Fe 14 B壳层中的Dy含量接近。GB扩散处理的磁体的高温退火（在900摄氏度下）导致GB层的消失，这导致磁性的大幅降低。这表明（Nd，Dy）（2）Fe 14 B壳层和富Nd GB相层都是GBDP提高矫顽力所需的微观结构特征。(c)2013 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
We discuss the mechanism of the coercivity enhancement by the grain boundary diffusion process (GBDP) using Dy vapor based on detailed microstructural characterizations. Scanning electron microscopy and electron probe microanalysis showed that a (Nd,Dy)(2) Fe14B shell formed in the outer region of Nd2Fe14B grains while its thickness decreased from the surface to the center of a cube-shaped sample. Atom probe tomography showed that the Dy content at grain boundaries (GBs) was close to that in the (Nd,Dy)(2)Fe14B shell. High-temperature annealing (at 900 degrees C) of a GB diffusion processed magnet led to the disappearance of the GB layers, which resulted in a substantial reduction in coercivity. This suggests that both the (Nd,Dy)(2)Fe14B shell and the Nd-rich GB phase layer are required microstructural features for the coercivity enhancement by the GBDP. (c) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.