Superior thermal and oxygen barrier properties of high-entropy ferroelastic rare earth tantalate(8RE_(1/8))TaO_(4)  

作　　者：Jun Wang Yongpan Zeng Xiaoyu Chong Manyu Zhang Qianqian Jin Yanjun Sun Xiangwei Tang Peng Wu Jing Feng 

机构地区：[1]Faculty of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China [2]Guangdong Midea Kitchen Appliances Manufacturing Co.,Ltd.,Midea Group,Foshan 528300,China [3]Materials Science and Engineering Research Center,Guangxi University of Science and Technology,Liuzhou 545006,China

出　　处：《Journal of Advanced Ceramics》2024年第12期2051-2067,共17页先进陶瓷(英文)

基　　金：supported by the National Natural Science Foundation of China(No.52402077);the Open Project of Shaanxi Laboratory(No.2021SXSYS-01-05);the Open Project of Yunnan Precious Metals Laboratory(No.YPML-2023050240);the Yunnan Fundamental Research Projects(Nos.202201BE070001-008,202201AT070192,and 202101BE070001-011).

摘　　要：Thermal/environmental barrier coatings(T/EBCs)are used to protect hot-section superalloys and/or ceramic matrix composite components from hot corrosion and oxidation;however,the majority of T/EBCs exhibit extremely high thermal and ionic conductivities.Here,we obtain a novel rare-earth tantalate with excellent oxygen and thermal insulation via a high-entropy strategy.The high-entropy component(8RE_(1/8))TaO_(4)(RE=rare earth),which is designed by large size disorder and mass disorder,has been reassembled into a stabilized monoclinic structure.(8RE_(1/8))TaO_(4)had 30.0%–31.1%and 59.2%–67.5%lower intrinsic thermal conductivity than single-RE RETaO_(4)and 8(Y_(2)O_(3)–ZrO_(2))8YSZ at 1200℃,respectively,and exhibited lower intrinsic thermal conductivity across the entire temperature range of 100–1200℃.This is the result of strong scattering by the phonon–phonon,grain boundary,domain boundary,dislocation,and vacancy defects.The ionic conductivity of(8RE_(1/8))TaO_(4)is 3712–29,667 times lower than that of 8YSZ at 900℃,benefiting from the strong Ta–O bonding strength,low concentration of mobile oxygen vacancies and severe lattice distortions that impede carrier transport.Moreover,(8RE_(1/8))TaO_(4)had superior high-temperature stability and excellent mechanical properties.Analysis of above results demonstrates that(8RE_(1/8))TaO_(4)is a promising candidate for T/EBCs.

关 键 词：thermal/environmental barrier coatings(T/EBCs) rare-earth tantalate high entropy thermal conductivity ionic conductivity 

分 类 号：TG1[金属学及工艺—金属学]