Microstructure regulation and optimizing magnetic properties of (La, Ce, Pr)17Fe78B6 alloy via short-range grain boundary diffusion
Microstructure regulation and optimizing magnetic properties of (La, Ce, Pr)17Fe78B6 alloy via short-range grain boundary diffusion
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DOI：
10.1016/j.jallcom.2023.170035
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发表时间：
2023-04
影响因子：
6.2
通讯作者：
Y. Hou;Z. Wu;H.F. Li;X.S. Zhang;W. Chai;Q. Feng;W. Li;X. Yu;Z. Pang;L. Ma;H.B. Yu;Y.L. Huang
中科院分区：
文献类型：
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作者：
Y. Hou;Z. Wu;H.F. Li;X.S. Zhang;W. Chai;Q. Feng;W. Li;X. Yu;Z. Pang;L. Ma;H.B. Yu;Y.L. Huang
提高稀土永磁体中La、Ce的利用率是解决稀土资源平衡利用的有效措施。本工作以纳米晶快淬态[(Ce0.7La0.3)0.3Pr0.7]17Fe78B6粉末和低熔点PrTbCu合金为原料和扩散源进行短程晶界扩散(SRGBD)以提高矫直力。获得了高达18.21 kOe的高矫顽力，比原始粉末提高了108.82%，而剩磁仅略有降低2.13%。在此基础上，采用放电等离子烧结(SPS)工艺制备了磁性能优良的纳米晶块体磁体。透射电子显微镜观察表明，短程晶界扩散诱导的bcc-RE2O3晶间相分布在相邻的基质相颗粒之间，有利于提高磁隔离效果。EDS结果表明，形成了具有高磁晶各向异性场的富Tb壳层。此外，在扩散初期，Tb元素比Pr元素更容易扩散到2：14：1相。增强的磁隔离效应和在颗粒表面形成的富Tb壳层有助于获得较高的矫直力。
Increasing the utilization ratio of La and Ce in rare earth permanent magnets is an effective measure to solve the balance utilization of rare earth resources. In this work, nanocrystalline melt spun [(Ce0.7La0.3)0.3Pr0.7]17Fe78B6powder and low melting point PrTbCu alloy were used as the initial material and the diffusion source for short-range grain boundary diffusion (SRGBD) to improve the coercivity. High coercivity of up to 18.21 kOe can be achieved, enhancing by 108.82% compared with the initial powder, and meanwhile, the remanence was only slightly reduced by 2.13%. After that, nanocrystalline bulk magnets with excellent magnetic performance were produced through spark plasma sintering (SPS). TEM observation reveals that the bcc-RE2O3intergranular phase that induced by short-range grain boundary diffusion is distributed between adjacent matrix phase grains, which is conductive to the improvement of magnetic isolation effect. EDS results show that the Tb-rich shell with high magnetocrystalline anisotropy field has formed. Moreover, it is found that Tb diffuses into the 2:14:1 phase more easily than Pr element during the initial stage of diffusion. Enhanced magnetic isolation effect and the formed Tb-rich shell in grain surface contributed to high coercivity.