Based on the highly efficient diffusion couple and equilibrated alloy methods, phase relations in La-Fe-B ternary system were experimentally investigated by scanning electron microscopy, electron probe microanalysis and electron backscatter diffraction techniques. Isothermal sections of the La-Fe-B system at both 600 and 800 °C were constructed. One ternary phase (LaFe 4 B 4 -τ 2 ) was detected at 600 °C and two ternary compounds (τ 2 and La 2 Fe 14 B-τ 1 ) were determined at 800 °C. Seven three-phase zones were found at 600 °C and ten three-phase regions were found at 800 °C. Liquid phase was found in the La-rich corner at 800 °C. The solid solubility of both binary and ternary compounds in the system is negligible. The present experimental results are important for the design of multi-main-phase Nd-La-Ce-Fe-B magnets.

中文翻译：

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La-Fe-B 体系中 600 和 800 °C 相平衡的实验研究

基于高效扩散偶和平衡合金方法，通过扫描电子显微镜、电子探针显微分析和电子背散射衍射技术，对La-Fe-B三元体系中的相关系进行了实验研究。构建了 La-Fe-B 系统在 600 和 800 °C 下的等温截面。一种三元相（LaFe 4 B 4 -τ 2 ）在 600 °C 下被检测到，两种三元化合物（τ 2 和 La 2 Fe 14 B-τ 1 ）在 800 °C 下被测定。在 600 °C 下发现了七个三相区，在 800 °C 下发现了十个三相区。在 800 °C 时在富含 La 的角落发现液相。二元和三元化合物在体系中的固溶度可以忽略不计。目前的实验结果对于多主相 Nd-La-Ce-Fe-B 磁体的设计很重要。