Enhanced coercivity of Nd-Ce-Fe-B sintered magnets by adding (Nd, Pr)-H powders
Enhanced coercivity of Nd-Ce-Fe-B sintered magnets by adding (Nd, Pr)-H powders
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添加(Nd, Pr)-H粉末增强Nd-Ce-Fe-B烧结磁体的矫顽力
DOI：
10.1016/j.jallcom.2017.05.257
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发表时间：
2017-10-15
影响因子：
6.2
通讯作者：
Yan, Mi
中科院分区：
文献类型：
--
作者：
Ma, Tianyu;Wu, Bo;Yan, Mi
近年来，将稀土Ce引入Nd-Fe-B系烧结磁体中引起了人们的极大兴趣。但Ce_2Fe_（14）B的各向异性场（HA）比Nd_2Fe_（14）B差，导致Nd-Ce-Fe-B磁体的矫顽力较低。为了进一步提高磁性，本工作采用（Nd，Pr）-H粉末作为晶界添加剂，对低成本（Nd，Pr）（22.3）Ces（8）.24FebaiBi（wt.%）烧结磁铁当（Nd，Pr）-H含量仅为2wt%时，Hcj从10.6kOe提高到12.7kOe，剩磁和最大能积略有降低。（Nd，Pr）-H在烧结过程中的脱氢作用促进了Nd和Pr向2：14：1相晶粒的扩散和晶界的光滑化。磁畴结构表征和微磁学模拟结果表明，富（Nd，Pr）壳层的形成和2：14：1相晶粒间的磁隔离效应使材料的磁性能明显增强。结果表明，通过晶界重组，可使Nd-Ce-Fe-B磁体的矫顽力提高到与商用Nd-Fe-B磁体相当的水平，为低成本稀土永磁材料的制备提供了新的思路。(C)2017爱思唯尔B. V.保留所有权利。
Incorporating the highly abundant rare earth (RE) Ce into Nd-Fe-B sintered magnets has attracted considerable interest recently. The inferior anisotropic field (HA) of Ce2Fe14B to Nd2Fe14B, however leads to low coercivity of the Nd-Ce-Fe-B magnets. To further enhance the coercivity, in this work, (Nd, Pr)-H powders were used as intergranular additive to restructure the grain boundaries of the low cost (Nd,Pr)(22.3)Ces(8).24FebaiBi (wt.%) sintered magnets. When added with only 2 wt% (Nd, Pr)-H, the Hcj can be enhanced from 10.6 kOe to 12.7 kOe with slight reduction in remanence and maximum energy product. The dehydrogenation of (Nd, Pr)-H during sintering promotes the diffusion of Nd and Pr towards the 2:14:1 phase grains and the smoothing of grain boundaries. The formation of (Nd, Pr)-rich shell with locally enhanced magnetocrystalline anisotropy and the magnetic isolation between adjacent 2:14:1 phase grains result in obvious coercivity enhancement, which was supported by magnetic domain structure characterizations and micromagnetic simulations. It suggests that through grain boundary restructuring, the coercivity of Nd-Ce-Fe-B magnets can be enhanced to be comparable of commercial Nd-Fe-B magnets, which may shed new insights into the fabrication of low cost RE permanent magnets. (C) 2017 Elsevier B.V. All rights reserved.