Directional solidification, nanoindentation and thermionic properties of LaB6(100)-ZrB2 eutectic composite. Issue 6 (June 2022)

• Record Type: Journal Article
• Authors: Yang, Xinyu; Deng, Chenhui; Gu, Zengjie; Shang, Jihua; Wang, Yan; Zhang, Jiuxing; Su, Haijun
• Is Part Of: Journal of the European Ceramic Society. Volume 42:Issue 6(2022)
• Page Start: 2726
• Page End: 2734
• Publication Date: 2022-06
• Subjects: LaB6 (100)-ZrB2 -- Eutectic composite -- Nanoindentation -- Thermionic emission -- Practical work function distribution (PWFD); Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2022.01.048
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: LaB6 (100)-ZrB2 eutectic composite was directionally solidified by optical floating melting zone at solidification rate V= 100 mm/h. It was shown that the stable eutectic growth can be achieved by periodic diverging and convergent growth, indicating that eutectic spacing was not unique value, but existed a limited range under a given rate. The atoms of the LaB6 (100)/ZrB2 interface were directly bonded. The mechanical property of the individual eutectic phase was evaluated by the nanoindentation. Both average Berkovich hardness and elastic modulus of LaB6 /ZrB2 phases was higher than that of LaB6 phase. Thermionic emission of DS LaB6 (100)-ZrB2 eutectic obeyed the Longo theory, indicating only the metal ceramic of LaB6 matrix in the composite emitted the electron. The practical work function distribution of DS LaB6 (100)-ZrB2 eutectic composite ranged from 2.51 to 3.18 eV, and the lowest work function was located around the LaB6 /ZrB2 interface, where had the highest current density