Phase evolution and thermal stability of novel high-entropy (Mo0.2Nb0.2Ta0.2V0.2W0.2)Si2 ceramics |
| |
| Affiliation: | 1. School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China;2. Department of Materials Science and Engineering, City University of Hong Kong, 999077, Hong Kong, China;1. Materials Science and Engineering Department, Missouri University of Science and Technology, Rolla, MO 65409, USA;2. Kansas City National Security Campus, Kansas City, MO 64147, USA;1. School of Materials Science and Physics, China University of Mining and Technology, Xuzhou 221116, China;2. College of Materials Science and Engineering, Xi’an University of Science and Technology, Xi’an, Shaanxi 710054, China;1. School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China;2. School of Mechanical Engineering, Dongguan University of Technology, Dongguan, Guangdong 523808, China;3. School of Energy, Power and Mechanical Engineering, North China Electric Power, University, Beijing 102206, China;1. School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China;2. Luoyang Institute of Science and Technology, Luoyang 471023, China;1. School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China;2. Defense Innovation Institute, Academy of Military Science, Beijing 100071, China;3. School of Material Science and Physics, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China |
| |
| Abstract: | Owing to the high melting points and high-temperature stability, transition-metal disilicides are potential components for aerospace, automotive, and industrial engineering applications. However, unwanted oxidation known as PEST oxidation severely limits their application owing to the formation of volatile transition metal oxides, especially in the temperature range of 500–1000 °C. To overcome this problem, a new class of high-entropy disilicides, (Mo0.2Nb0.2Ta0.2V0.2W0.2)Si2, was selected by first-principles calculations and then successfully fabricated using a hot-pressing sintering technique. Furthermore, the phase evolution, thermal expansion behavior, thermal conductivity, and oxidation behavior were systematically investigated. Compared with MoSi2, (Mo0.2Nb0.2Ta0.2V0.2W0.2)Si2 possessed a lower thermal conductivity (10.9–14.7 W·m?1·K?1) at 25–1000 °C, higher thermal expansion coefficients (8.6 ± 1.3–6 K–1) at 50–1200 °C, and especially an excellent thermal stability at 500–1000 °C owing to slow diffusion and selective oxidation. This work provides a strong foundation for the synthesis and application of high-entropy disilicides. |
| |
| Keywords: | High-entropy disilicides First-principles calculations Phase evolution Thermal stability |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
