Rare-earth-niobate high-entropy ceramic foams with enhanced thermal insulation performance  

作　　者：R.W.Yang Y.P.Liang J.Xu X.Y.Meng J.T.Zhu S.Y.Cao M.Y.Wei R.X.Zhang J.L.Yang F.Gao 

机构地区：[1]State Key Laboratory of Solidification Processing,MIIT Key Laboratory of Radiation Detection Materials and Devices,School of Materials Science and Engineering,Northwestern Polytechnical University,Xi’an,710072,China [2]NPU-QMUL Joint Research Institute of Advanced Materials and Structure,Northwestern Polytechnical University,Xi’an,710072,China [3]State Key Laboratory of New Ceramics and Fine Processing,School of Materials Science and Engineering,Tsinghua University,Beijing,100084,China [4]State Key Laboratory of Materials Processing and Die&Mould Technology,School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan,430074,China

出　　处：《Journal of Materials Science & Technology》2022年第21期94-102,共9页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.52072301);the State Key Laboratory of Solidification Processing(NPU)(No.2021-TS-08);the State Key Laboratory of New Ceramic and Fine Processing Tsinghua University(No.KFZD202102);the China-Poland International Collaboration Fund of National Natural Science Foundation of China(No.51961135301);the Fundamental Research Funds for the Central Universities(No.D5000210722);State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology(No.P2020–009)。

摘　　要：The introduction of porous structures into high-entropy ceramics is expected to further improve its thermal insulation performance.In this work,a series of novel rare-earth-niobate high-entropy ceramic foams((Dy_(0.2)Ho_(0.2)Y_(0.2)Er_(0.2)Yb_(0.2))_(3)NbO_(7))with hierarchical pore structures were prepared by a particle-stabilized foaming method.Atomic-scale analysis reveals that high entropy causes atom displacement and lattice distortion.The high-entropy ceramic foams exhibit high porosity(90.13%-96.13%)and ultralow thermal conductivity(0.0343-0.0592 W/(m·K))at room temperature.High-entropy ceramic foam prepared by a 20 wt%slurry sintered at 1500℃has the porosity of 96.12%and extremely low thermal conductivity of 0.0343 W/(m·K).The existence of walls and secondary pores contributes to reduced thermal conductivity.There is a temperature difference of over 800℃between frontside and backside of the sample under fire resistance test.The research indicates that these as-prepared high-entropy ceramic foams are expected to be promising thermal insulation materials.

关 键 词：Rare-earth niobate High-entropy ceramic foams Particle-stabilized foaming Atomic-scale analysis Thermal conductivity 

分 类 号：TQ174.1[化学工程—陶瓷工业]