不同生长速度La0.6Ce0.3Pr0.1B6-ZrB2定向凝固共晶材料结构和性能的研究  

Structure and Properties of La0.6Ce0.3Pr0.1B6-ZrB2,a Directionally Solidified Eutectic with Different Growth

作　　者：石峰 SHI Feng(Beijing Beiye Functional Materials Corporation,Beijing 100192)

机构地区：[1]北京北冶功能材料有限公司,北京100192

出　　处：《金属材料研究》2023年第1期16-22,4,共8页Research on Metallic Materials

摘　　要：La0.6Ce0.3Pr0.1B6-ZrB2定向凝固共晶(directionally solidified eutecticDSE)是一种极具应用前景的高性能电子发射材料。本文研究了此定向凝固共晶材料的生长速度对于材料微观结构、生长方向、取向关系、力学性能的影响。实验结果显示共晶材料的微观结构和两相生长方向随生长速度变化:生长速度增加,ZrB,相的均匀性降低;而且La0.6Ce0.3Pr0.1B6-ZrB2基体和ZrB,第二相的生长方向也发生变化。生长速度为100mm/h的共晶合金中,两相具有唯一的生长方向和晶体学取向关系。与单晶的La0.6Ce0.3Pr0.1B6相比,La0.6Ce0.3Pr0.1B6-ZrB2的断裂韧性提高了最少50%,不同生长速度的共晶材料断裂韧性也不相同。La0.6Ce0.3Pr0.1B6-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,and mechanical properties were 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 ZrB,phase became,and the growth directions of the La0.6Ce0.3Pr0.1B6.matrix and the ZrB2 phase were also altered accordingly.In the La0.6Ce0.3Pr0.1B6-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 La0.6Ce0.3Pr0.1B6-ZrB2,DSE is at least 50%higher than that of the single crystal La0.6Ce0.3Pr0.1B6,and the fracture toughness of the DSEs formed at different growth rates also differed.

关 键 词：La0.6Ce0.3Pr0.1B6-ZrB2 DSE 微观结构 机械性能 

分 类 号：TG1[金属学及工艺—金属学]