Abstract 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 (Nd0.75LRE0.25)30.5FebalAl0.1Cu0.1B1 (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.

中文翻译：

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高丰度稀土元素LRE（La、Ce和Y）的全过程冶金行为和Nd 0.75 LRE 0.25 -Fe-B烧结磁体的磁性能

摘要 La、Ce和Y等高丰度稀土元素的平衡利用因其经济和环境优势引起了工业和科学界的极大兴趣。关键问题之一是了解高丰度稀土元素的全过程冶金行为，以优化含有高浓度稀土元素的 RE-Fe-B 烧结磁体的显微结构以获得高磁性能。高丰度的稀土元素。在这项工作中，我们系统地表征了磁铁 (Nd0.75LRE0.25)30.5FebalAl0.1Cu0.1B1 (LRE = La, Ce 和 Y, wt. %) 在带材铸造、烧结和退火的整个过程中的冶金行为. 在带材连铸 (SC) 期间，La和Ce主要分布在晶界相中，而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的基体相中被挤出，在晶界偏析，而Ce和Y则从晶界迁移到2:14:1的基体相。Nd-La/Ce/Y-Fe-B的基体相和晶界相的晶体结构为四方相（空间群P42/mnm）和hcp-Re2O3。Nd-La/Ce/Y-Fe-B 磁体晶界的研究表明，Ce 磁体的晶界比 La 和 Y 磁体的晶界厚。元素 La、Ce 和Y 归因于不同的凝固温度和 Re2Fe14B 相的置换能。在含Y磁铁的情况下形成核壳晶粒结构。元素分析表明，Y 更倾向于位于晶界的核心，而 Nd 分布在晶界的壳中。