High-entropy rare-earth zirconate ceramics with low thermal conductivity for advanced thermal-barrier coatings  

作　　者：Debao LIU Baolu SHI Liyan GENG Yiguang WANG Baosheng XU Yanfei CHEN 

机构地区：[1]Institute of Advanced Structure Technology,Beijing Institute of Technology,Beijing 100081,China [2]Shanghai Space Propulsion Technology Research Institute,Shanghai 201109,China

出　　处：《Journal of Advanced Ceramics》2022年第6期961-973,共13页先进陶瓷（英文）

基　　金：This work is supported by the National Science and Technology Major Project(2017-VI-0020-0093);the National Natural Science Foundation of China(12090031).

摘　　要：The high-entropy rare-earth zirconate((La_(0.2)Nd_(0.2)Sm_(0.2)Gd_(0.2)Yb_(0.2))_(2)Zr_(2)O_(7),5RE_(2)Zr_(2)O_(7)HEREZs)ceramics were successfully prepared by a new high-speed positive grinding strategy combined with solid-state reaction method.The microstructure,crystal structure,phase composition,and thermophysical and mechanical properties of the samples were systematically investigated through various methods.Results indicate that the samples have a single-phase defect fluorite-type crystal structure with excellent high-temperature thermal stability.The as-prepared samples also demonstrate low thermal conductivity(0.9–1.72 W·m^(−1)·K^(−1)at 273–1273 K)and high coefficient of thermal expansion(CTE,10.9×10^(−6)K^(−1)at 1273 K),as well as outstanding mechanical properties including large Young’s modulus(E=186–257 GPa)and high fracture toughness(KIC).Furthermore,the formation possibility of the as-prepared samples was verified through the first-principles calculations,which suggested the feasibility to form the 5RE_(2)Zr_(2)O_(7)HE-REZs in the thermodynamic direction.Therefore,in view of the excellent multifunctional properties exhibited by the as-prepared 5RE_(2)Zr_(2)O_(7)HE-REZs,they have great potential applications in next-generation thermal-barrier coatings(TBCs).

关 键 词：high-entropy rare-earth zirconates(HE-REZs) first-principles calculations thermal conductivity thermal stability Young’s modulus thermal-barrier coatings(TBCs) 

分 类 号：TQ174[化学工程—陶瓷工业]