Coercivity enhancement of Nd-Fe-B sintered magnets with intergranular adding (Pr, Dy, Cu)-Hx powders
Coercivity enhancement of Nd-Fe-B sintered magnets with intergranular adding (Pr, Dy, Cu)-Hx powders
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DOI：
10.1016/j.jmmm.2015.09.071
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发表时间：
2016-02-01
影响因子：
2.7
通讯作者：
Yan, Mi
中科院分区：
文献类型：
--
作者：
Zhang, Yujing;Ma, Tianyu;Yan, Mi
通过向Nd-Fe-B系烧结磁体晶间添加Dy源形成Nd 2Fe 14 B/（Nd，Dy）（2）Fe 14 B核壳结构，可有效提高磁体的矫顽力，同时降低剩磁损失。然而，过量的Dy位于晶间区几乎没有硬磁贡献，导致其利用效率低。本工作制备了稀释Dy粉末（Pr_（37）Dy_（30）Cu_（33））-H-x，并通过双合金化方法将其掺入Nd-Fe-B烧结磁体中。当（Pr，Dy，Cu）-H-x的加入量为2.0wt%（Dy的当量仅为0.32at%）时，体系的矫顽力从15.0 kOe迅速提高到182 kOe，提高了21.3%。推导出的矫顽力增量比为10.0kOe/单位Dy at%。在烧结过程中，（Pr，Dy，Cu）-H-x发生脱氢反应，有利于Dy向2：14：1相晶粒的扩散，并使晶界变得光滑。增强的局部各向异性场和良好解耦的2：14：1相晶粒有助于这种快速的双折射率增强。研究结果表明，添加稀Dy可用于制备高矫顽力、低稀土消耗的Nd-Fe-B系烧结磁体。(C)2015 Elsevier B. V.版权所有。
Forming Nd2Fe14B/(Nd, Dy)(2)Fe14B core-shell structure by intergranular adding Dy-containing sources into Nd-Fe-B sintered magnets is effective to improve coercivity and to minimize remanence loss simultaneously. However, the excessive Dy located in the intergranular regions has nearly no hard magnetic contribution, causing its low utilization efficiency. In this work, diluted Dy powders (Pr37Dy30Cu33)-H-x were prepared and incorporated into Nd-Fe-B sintered magnets via a dual-alloy approach. The coercivity increases rapidly from 15.0 to 182 kOe by 21.3% with 2.0 wt% (Pr, Dy, Cu)-H-x addition (the equivalent Dy is only 0.32 at%). The deduced coercivity incremental ratio is 10.0 kOe per unit Dy at%. Dehydrogenation reaction of (Pr, Dy, Cu)-H-x occurs during sintering, which favors Dy diffusion towards the 2:14:1 phase grains as well as smoothing the grain boundaries (GBs). The enhanced local anisotropic field and the well decoupled 2:14:1 phase grains contribute to such rapid coercivity enhancement. This work suggests that adding diluted Dy hydrides is promising for fabricating high coercivity Nd-Fe-B sintered magnets with less heavy rare-earth consumption. (C) 2015 Elsevier B.V. All rights reserved.