Medium-entropy(Me,Ti)_(0.1)(Zr,Hf,Ce)_(0.9)O_(2)(Me=Y and Ta):Promising thermal barrier materials for high-temperature thermal radiation shielding and CMAS blocking  

作　　者：Shuaihang Qiu Huimin Xiang Fu-Zhi Dai Hailong Wang Muzhang Huang Chunlei Wan Qing Meng Jiangtao Li Xiaohui Wang Yanchun Zhou 

机构地区：[1]Science and Technology on Advanced Functional Composite Laboratory,Aerospace Research Institute of Materials and Processing Technology,Beijing 100076,China [2]State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology,Wuhan 430070,China [3]School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,China [4]State Key Lab of New Ceramics and Fine Processing,School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China [5]Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190,China [6]Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China

出　　处：《Journal of Materials Science & Technology》2022年第28期144-153,共10页材料科学技术（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.51772275 and No.51972089);Distinguished Young Foundation of Henan Province(No.202300410355)。

摘　　要：With continuous enhancement of gas-turbine inlet temperature and rapid increase of radiant heat transfer,thermal barrier coating(TBC)materials with a combination of low thermal conductivity and good high-temperature thermal radiation shielding performance play vital roles in ensuring the durability of metallic blades.However,yttria-stabilized zirconia(YSZ),as the state-of-the-art TBC and current industry standard,is unable to meet such demands since it is almost translucent to high-temperature thermal radiation.Besides,poor corrosion resistance of YSZ to molten calcia-magnesia-alumina-silicates(CMAS)also impedes its application in sand,dust,or volcanic ash laden environments.In order to improve the hightemperature thermal radiation shielding performance and CMAS resistance of YSZ and further reduce its thermal conductivity,two medium-entropy(ME)oxide ceramics,ME(Y,Ti)_(0.1)(Zr,Hf,Ce)_(0.9)O_(2)and ME(Ta,Ti)_(0.1)(Zr,Hf,Ce)_(0.9)O_(2),were designed and prepared by pressureless sintering of binary powder compacts in this work.ME(Y,Ti)_(0.1)(Zr,Hf,Ce)_(0.9)O_(2)presents cubic structure but a trace amount of secondary phase,while ME(Ta,Ti)_(0.1)(Zr,Hf,Ce)_(0.9)O_(2)displays a combination of tetragonal phase(81.6 wt.%)and cubic phase(18.4 wt.%).Both ME(Y,Ti)_(0.1)(Zr,Hf,Ce)_(0.9)O_(2)and ME(Ta,Ti)_(0.1)(Zr,Hf,Ce)_(0.9)O_(2)possess better high-temperature thermal radiation shielding performance than YSZ.Especially,the high-temperature thermal radiation shielding performance of ME(Ta,Ti)_(0.1)(Zr,Hf,Ce)_(0.9)O_(2)is superior to that of ME(Y,Ti)_(0.1)(Zr,Hf,Ce)_(0.9)O_(2)due to its narrower band gap and correspondingly higher infrared absorbance(above 0.7)at the waveband of 1 to 5μm.The two ME oxides also display significantly lower thermal conductivity than YSZ and close thermal expansion coefficients(TECs)to YSZ and Ni-based superalloys.In addition,the two ME oxides possess excellent CMAS resistance.After attack by molten CMAS at 1250℃for 4 h,merely~2μm thick penetration layer has been formed and the structure belo

关 键 词：Medium-entropy ceramics Thermal barrier coatings Thermal radiation shielding CMAS resistance Infrared absorbance 

分 类 号：TG174.4[金属学及工艺—金属表面处理] TK123[金属学及工艺—金属学]