La_0.6Ce_0.3Pr_0.1B₆-ZrB₂, a directionally solidified eutectic (DSE), is a material with a high-performance thermionic emission with great application prospects. The influence of the growth rates of this DSE on the microstructure, growth direction, two phases orientation relationship, mechanical properties, and thermionic emission properties was investigated. The experimental results show that the microstructure and growth direction of the two phases varied with the growth rate of the eutectic: the faster the growth rate, the lower the uniformity of the ZrB₂ phase became, and the growth directions of the La_0.6Ce_0.3Pr_0.1B₆ matrix and the ZrB₂ phase were also altered accordingly. In the La_0.6Ce_0.3Pr_0.1B₆-ZrB₂ DSE with a growth rate of 100 mm/h, the two phases have a unique growth direction and a crystallographic orientation relationship. The fracture toughness of the La_0.6Ce_0.3Pr_0.1B₆-ZrB₂ DSE is at least 50% higher than that of the single crystal La_0.6Ce_0.3Pr_0.1B₆, and the fracture toughness of the DSEs formed at different growth rates also differed.

中文翻译：

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La0.6Ce0.3Pr0.1B6-ZrB2的结构和性能，一种具有不同生长速率的定向凝固共晶

La _0.6 Ce _0.3 Pr _0.1 B ₆ -ZrB ₂是一种定向凝固共晶（DSE）材料，是一种具有良好应用前景的高性能热电子发射材料。研究了该 DSE 的生长速率对微观结构、生长方向、两相取向关系、机械性能和热电子发射性能的影响。实验结果表明，两相的显微组织和生长方向随共晶的生长速度而变化：生长速度越快，ZrB ₂相的均匀性越低，La _0.6 Ce _0.3的生长方向PR _0.1B ₆基体和ZrB ₂相也相应地改变。在生长速率为100 mm/h的La _0.6 Ce _0.3 Pr _0.1 B ₆ -ZrB ₂ DSE中，两相具有独特的生长方向和晶体取向关系。La _0.6 Ce _0.3 Pr _0.1 B ₆ -ZrB ₂ DSE的断裂韧性比单晶La _0.6 Ce _0.3 Pr _0.1 B ₆的断裂韧性至少高50%，不同生长速率下形成的 DSE 的断裂韧性也不同。