Journal of Inorganic Materials ›› 2021, Vol. 36 ›› Issue (4): 405-410.DOI: 10.15541/jim20200489

Special Issue: 【结构材料】热障与环境障涂层 【结构材料】高熵陶瓷

• RESEARCH PAPER • Previous Articles     Next Articles

Preparation and Thermophysical Properties of (Sm0.2Gd0.2Dy0.2Y0.2Yb0.2)3TaO7 High-entropy Ceramic

SANG Weiwei1,2(), ZHANG Hongsong2(), CHEN Huahui1, WEN Bin2, LI Xinchun2   

  1. 1. School of Mechanical Electronic & Information Engineering, China University of Mining & Technology-Beijing, Beijing 10083, China
    2. College of Mechanical Engineering, Henan University of Engineering, Zhengzhou 451191, China
  • Received:2020-08-24 Revised:2020-10-05 Published:2021-04-20 Online:2020-10-30
  • Contact: ZHANG Hongsong, professor. E-mail: zhsandchen@126.com
  • About author:SANG Weiwei(1982-), female, PhD candidate, lecturer. E-mail: lyftt0602@126.com
  • Supported by:
    Henan Province University Scientific and Technological Innovation Team (18IRTSHN005); Key Project of Science and Technology Research at Henan Province Department of Education (20A5600008)

Abstract:

Developing novel ceramic materials with excellent thermophysical properties is one of the hotspots in the field of thermal barrier coatings. The (Sm0.2Gd0.2Dy0.2Y0.2Yb0.2)3TaO7 high-entropy ceramic was fabricated via high-temperature solid-state reaction. The crystal structure, microstructure, phase stability and thermophysical properties were investigated. Results indicate that (Sm0.2Gd0.2Dy0.2Y0.2Yb0.2)3TaO7 high-entropy ceramic has single defective fluorite structure, its elements are homogenously distributed, its grain size ranges from 0.2 to 3 μm. After high-temperature thermal cycling, the sample still remains single fluorite structure, showing excelleent phase stability at high temperature. Thermal conductivity lies in the range of 0.72-0.74 W/(m·K), lower than that of 7YSZ. Thermal expansion coefficient at 1200 ℃ is 5.6×10-6 K-1, lower than requirement of thermal barrier coatings (TBCs) for surface ceramic layer. However, its thermal expansion coefficient is close to that of the silicon-based ceramics substrate of environmental barrier coatings (EBCs) ((3.4-5.5)×10-6 K-1).

Key words: high-entropy ceramic, thermal-barrier coating, thermal conductivity, thermal expansion coefficient

CLC Number: