Synergistic effects of high-entropy engineering and particulate toughening on the properties of rare-earth aluminate-based ceramic composites  

作　　者：Tian-Zhe Tu Ji-Xuan Liu Yue Wu Lin Zhou Yongcheng Liang Guo-Jun Zhang 

机构地区：[1]State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,College of Materials Science and Engineering,College of Science,Institute of Functional Materials,Donghua University,Shanghai 201620,China

出　　处：《Journal of Advanced Ceramics》2023年第4期861-872,共12页先进陶瓷（英文）

基　　金：financial supports from the National Natural Science Foundation of China(Nos.52032001 and 52211540004);the Fundamental Research Funds for the Central Universities(No.2232021A-01).

摘　　要：Rare-earth aluminates(REAIOs)are potential thermal barrier coating(TBC)materials,but the relatively high thermal conductivity(ko,~13.6 W·m^(-1)·K^(-1))and low fracture toughness(K_(1c),-1.9 MPa·m^(1/2))limit their application.This work proposed a strategy to improve their properties through the synergistic effects of high-entropy engineering and particulate toughening.High-entropy(La_(0.2)Nd_(0.2)Sm_(0.2)Eu_(0.2)Gd_(0.2)AlO_(3))(HEAO)-based particulate composites with different contents of high-entropy(La_(0.2)Nd_(0.2)Sm_(0.2)Eu_(0.2)Gd_(0.2))_(2)Zr_(2)O_(7)(HEZO)were designed and successfully prepared by solid-state sintering.The high-entropy feature of both the matrix and secondary phases causes the strong phonon scattering and the incorporation of the HEZO secondary phase,remarkedly inhibiting the grain growth of the HEAO phase.As a result,HEAO-xHEZO(x=0,5%,10%,25%,and 50%in volume)ceramic composites show low thermal conductivity and high fracture toughness.Compared to the most commonly applied TBC material-yttria stabilized-zirconia(YSZ),the HEAO-25%HEZO particulate composite has a lower thermal conductivity of 0.96-1.17 W·m^(-1)·K^(-1)(298-1273 K),enhanced fracture toughness of 3.94±0.35 MPa-m,and comparable linear coefficient of thermal expansion(CTE)of 10.5×10^(-6)K^(-1).It is believed that the proposed strategy should be revelatory for the design of new coating materials including TBCs and environmental barrier coatings(EBCs).

关 键 词：high-entropy particulate composites thermal barrier coating(TBC) thermal properties mechanical properties fine grains 

分 类 号：TQ174.1[化学工程—陶瓷工业]