Phase evolution, microstructure and magnetic properties of bulk α-Fe/Nd2Fe14B nanocomposite magnets prepared by severe plastic deformation and thermal annealing
Phase evolution, microstructure and magnetic properties of bulk α-Fe/Nd2Fe14B nanocomposite magnets prepared by severe plastic deformation and thermal annealing
复制标题
剧烈塑性变形和热退火制备块体α-Fe/Nd2Fe14B纳米复合磁体的相演化、微观结构和磁性能
DOI：
10.1016/j.jallcom.2015.08.132
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发表时间：
2015-12-05
影响因子：
6.2
通讯作者：
Zhang, Xiangyi
中科院分区：
文献类型：
--
作者：
Li, Hailing;Li, Wei;Zhang, Xiangyi
研究了大塑性变形（SPD）结合热退火制备的α-Fe/Nd 2Fe 14 B纳米复合磁体的相演变、显微结构和磁性能。实验结果表明，SPD对（Nd，Pr）-Fe-Co-Nb-B合金退火过程中的相演变有显著影响。当应变ε增加到ε = 6.1时，合金中亚稳中间相如Nd 2Fe 23 B3和Fe 3B的形成被有效地抑制，在块状α-Fe/Nd 2Fe 14 B磁体中产生高体积分数的α-Fe相（V-c类似于37%）。α-Fe和Nd_2Fe_（14）B相的晶粒尺寸随应变的增加而减小。α-Fe和Nd_2Fe_（14）B的晶粒尺寸分别为13.3 nm和26.5 nm，磁性能分别为（BH）（max）= 14.9 MGOe和H-c = 6.4 kOe，均大于直接退火非晶带制备的α-Fe/Nd_2Fe_（14）B磁体。（BH）（max）= 10.3 MGOe和H-c = 4.6 kOe。SPD磁体的磁化率的增强是由于畴壁钉扎强度的增加。(C)2015 Elsevier B. V.版权所有。
In this study, the phase evolution, microstructure and magnetic properties of bulk alpha-Fe/Nd2Fe14B nanocomposite magnets prepared by a combination of severe plastic deformation (SPD) and thermal annealing have been investigated. Experimental results demonstrate that SPD affects the phase evolution of (Nd,Pr)-Fe-Co-Nb-B alloy upon annealing significantly. The formation of metastable intermediate phases, such as Nd2Fe23B3 and Fe3B, in the alloy has been effectively inhibited as the strain epsilon is increased to epsilon = 6.1, yielding a high volume fraction of alpha-Fe phase (V-c similar to 37%) in the bulk alpha-Fe/Nd2Fe14B magnets. The grain size of alpha-Fe and Nd2Fe14B phases in the magnets decreases with increasing strain. A smaller grain size d = 13.3 nm for alpha-Fe and 26.5 nm for Nd2Fe14B is achieved at epsilon = 6.1, and the magnets show the magnetic properties, (BH)(max) = 14.9 MGOe and H-c = 6.4 kOe, larger than those in the alpha-Fe/Nd2Fe14B magnets made by directly annealing amorphous ribbons, (BH)(max) = 10.3 MGOe and H-c = 4.6 kOe. The enhanced coercivity in the SPD magnets results from an increase in domain-wall-pinning strength. (C) 2015 Elsevier B.V. All rights reserved.