Whole process metallurgical behavior of the high-abundance rare-earth elements LRE (La, Ce and Y) and the magnetic performance of Nd0.75LRE0.25-Fe-B sintered magnets
Whole process metallurgical behavior of the high-abundance rare-earth elements LRE (La, Ce and Y) and the magnetic performance of Nd0.75LRE0.25-Fe-B sintered magnets
复制标题
高丰度稀土元素LRE（La、Ce、Y）全过程冶金行为及Nd0.75LRE0.25-Fe-B烧结磁体的磁性能
DOI：
10.1016/j.actamat.2018.05.046
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发表时间：
2018-08-01
期刊：
影响因子：
9.4
通讯作者：
Yan, Aru
中科院分区：
文献类型：
--
作者：
Fan, Xiaodong;Ding, Guangfei;Yan, Aru
高丰度稀土元素La、Ce和Y的平衡利用由于其经济和环境效益而引起了工业和科学界的极大兴趣。了解高丰度稀土元素的全过程冶金行为，优化高丰度稀土含量的RE-Fe-B系烧结磁体的微观结构，提高磁体的磁性能，是研究的关键问题之一。本文系统地研究了（Nd_（0.25）LRE_（0.25））（30.5）FebalAl_（0.1）Cu_（0.1）B_1（LRE = La，Ce和Y，wt. %).在薄带连铸（SC）过程中，La和Ce主要分布在晶界相，Y均匀分布在2：14：1的基体相晶粒中。在烧结和退火过程中，La从2：14：1基体相中被挤出，偏聚在晶界上，而Ce和Y则从晶界迁移到2：14：1基体相中。Nd-La/Ce/Y-Fe-B的基体相和晶界相均为四方相（空间群为P42/mnm）和hcp-Re 2 O 3。对Nd-La/Ce/Y-Fe-B磁体晶界的研究表明，添加Ce的磁体晶界比添加La和Y的磁体晶界厚。稀土元素La、Ce和Y的不同冶金行为是由于Re 2Fe 14 B相的凝固温度和置换能不同所致。在含Y磁体的情况下形成核壳晶粒结构。元素分析表明，Y倾向于位于晶界的核部，Nd则分布在晶界的壳部。(C)2018 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Balanced usages of the high-abundance rare-earth elements, such as La, Ce and Y, have attracted tremendous interests of the industrial and scientific societies because of the economic and environmental merits. One of the key issues is of understanding the whole process metallurgical behavior of the high-abundance rare-earth elements in order to optimize the microstructures for a high magnetic performance of the RE-Fe-B sintered magnets, which contain a high concentration of the high-abundance rare-earth elements. In this work, we systematically characterized the metallurgical behaviors during the whole process of strip casting, sintering and annealing for the magnets (Nd0.25LRE0.25)(30.5)FebalAl0.1Cu0.1B1 (LRE = La, Ce and Y, wt. %). During the strip casting (SC), La and Ce mainly distribute in the grain boundary phase while Y distributes uniformly in the 2:14:1 matrix phase grains. Under the sintering and annealing, La is squeezed out from the 2:14:1 matrix phase to segregate in the grain boundaries, while Ce and Y migrate from the grain boundary to the 2:14:1 matrix phase. The crystalline structures of matrix phase and grain boundary phase of Nd-La/Ce/Y-Fe-B are tetragonal phase (space group P42/mnm) and hcp-Re2O3. The investigations of the grain boundary of Nd-La/Ce/Y-Fe-B magnets demonstrate that the grain boundary of the magnet with Ce is thicker than that of magnets with La and Y. The different metallurgical behaviors of elements La, Ce and Y are attributed to the different solidification temperature and substitution energy of Re2Fe14B phases. Core-shell grain structure was formed in the case of Y-containing magnets. Elemental analysis demonstrates that Y prefers to locate in the core of the grain boundary and Nd distributes in the shell of the grain boundary. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.