High entropy(Y0.2Yb0.2Lu0.2Eu0.2Er0.2)3Al5O12:A novel high temperature stable thermal barrier material

作     者：Heng Chen Zifan Zhao Huimin Xiang Fu-Zhi Dai Wei Xu Kuang Sun Jiachen Liu Yanchun Zhou Heng Chen;Zifan Zhao;Huimin Xiang;Fu-Zhi Dai;Wei Xu;Kuang Sun;Jiachen Liu;Yanchun Zhou

作者机构：Science and Technology on Advanced Functional Composite LaboratoryAerospace Research Institute of Materials&Processing TechnologyBeijing100076China Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of EducationSchool of Materials Science and EngineeringTianjin UniversityTianjin300072China Shanghai Chenhua Science and Technology Corporation LimtedShanghai201804China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2020年第47卷第13期

页      面：57-62页

核心收录：

学科分类：080503[工学-材料加工工程] 08[工学] 0806[工学-冶金工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：financial supported by the National Natural Science Foundation of China(Nos.51672064 and U1435206)。 

主　　题：High entropy ceramics (Y0.2Yb0.2Lu0.2Eu0.2Er0.2)3Al5O12 Thermal barrier coatings Thermal conductivity Garnet 

摘      要：Ytterbium aluminum garnet(Yb3Al5O12)is considered as a promising thermal barrier material.However,the main limitations of Yb3Al5O12 for thermal barrier applications are relative low thermal expansion coefficient and high thermal conductivity.In order to overcome these obstacles,herein,a new high entropy(Y0.2Yb0.2Lu0.2Eu0.2Er0.2)3Al5O12 ceramic was designed,and then powders and bulk were prepared through solid-state reaction method and spark plasma sintering(SPS),respectively.The thermal expansion coefficient of HE(Y0.2Yb0.2Lu0.2Eu0.2Er0.2)3Al5O12 is(8.54±0.29)×10^-6 K^-1 at 673 K–1273 K,which is about 9%higher than that of Yb3Al5O12.The thermal conductivity of HE(Y0.2Yb0.2Lu0.2Eu0.2Er0.2)3Al5O12 ceramic is 3.81 W·m^-1 K^-1 at 300 K,which is about 18%lower than that of Yb3Al5O12.Moreover,there is no reaction between HE(Y0.2Yb0.2Lu0.2Eu0.2Er0.2)3Al5O12 and thermally grown(TG)Al2O3 even at 1600℃.After annealing at 1590℃for 18 h,the average grain size of HE(Y0.2Yb0.2Lu0.2Eu0.2Er0.2)3Al5O12 increases only from 1.56μm to 2.27μm.Close thermal expansion coefficient to TG Al2O3,low thermal conductivity,good phase stability,excellent chemical compatibility with TG Al2O3 and slow grain growth rate make HE(Y0.2Yb0.2Lu0.2Eu0.2Er0.2)3Al5O12 promising for thermal barrier applications.