热障涂层用(Sm_(0.5)Yb_(0.5))_(3)TaO_(7)陶瓷的热物理性能  

Thermophysical Properties of(Sm_(0.5)Yb_(0.5))_(3)TaO_(7) Ceramics for Thermal Barrier Coating Applications

作　　者：郭怡 牛苗苗 GUO Yi;NIU Miaomiao(School of Intelligent Manufacturing,Chongqing Water Resources and Electric Engineering College,Chongqing 402160,China)

机构地区：[1]重庆水利电力职业技术学院智能制造学院,重庆402160

出　　处：《人工晶体学报》2024年第12期2066-2072,共7页Journal of Synthetic Crystals

基　　金：重庆市教委科学技术研究项目(KJQN202303810);重庆水利电力职业技术学院科研项目(K202317)。

摘　　要：为开发性能优异的新型热障涂层表面陶瓷层材料,探索Yb掺杂对Sm_(3)TaO_(7)热物理性能的影响,采用高温固相反应法,成功制备了(Sm_(0.5)Yb_(0.5))_(3)TaO_(7)陶瓷,并对其晶体结构、微观结构、元素含量、热物理和高温相稳定性能进行了研究。结果表明,制备的(Sm_(0.5)Yb_(0.5))_(3)TaO_(7)陶瓷具有单一焦绿石结构,致密的显微组织,制备过程中无元素损失现象发生。元素掺杂增加了声子散射程度,(Sm_(0.5)Yb_(0.5))_(3)TaO_(7)热导率明显降低,其高温热导率仅为1.02 W/(m·K),远低于Sm_(3)TaO_(7)和Yb_(3)TaO_(7)的1.31 W/(m·K)和1.14 W/(m·K)。由于掺杂离子Yb^(3+)较低的电负性,其在1300℃时的热膨胀系数为9.92×10^(-6) K^(-1),热膨胀系数明显高于Sm_(3)TaO_(7),与YSZ和La_(2)Zr_(2)O_(7)的热膨胀系数在同一数量级。其热导率和热膨胀系数满足热障涂层的要求,在室温至1300℃表现出良好的高温相稳定性能。In this paper,(Sm_(0.5)Yb_(0.5))_(3)TaO_(7) was prepared via solid-reaction method in order to develop a novel ceramic layer material with excellent performance for thermal barrier coating and explore the influence of Yb addition on thermophysical performances of Sm_(3)TaO_(7).Its crystal structure,microstructure,element composition,thermophysical performances and phasestability at high temperatures were investigated.The final results indicate that the synthesized(Sm_(0.5)Yb_(0.5))_(3)TaO_(7) is of single pyrochlore-type lattice-structure,and compact microstructure,no element loss is found in the synthesis procedure.Owing to phonon scattering caused by doping cations,the thermal conductivity of(Sm_(0.5)Yb_(0.5))_(3)TaO_(7) reduces.Its thermal conductivity at high-temperature is about 1.02 W/(m·K),which is less than that of Sm_(3)TaO_(7)(1.31 W/(m·K))and Yb3 TaO7(1.14 W/(m·K)).Because of low electronegativity of Yb^(3+),its thermal expansion coefficient at 1300℃ is about 9.92×10^(-6) K^(-1).Its thermal expansion coefficient is higher than that of Sm_(3)TaO_(7) and lies in the same order with that of YSZ and La_(2)Zr_(2)O_(7).The thermal conductivity and expansion coefficient of synthesized(Sm_(0.5)Yb_(0.5))_(3)TaO_(7) meet the requirements for thermal barrier coatings.This oxide also shows excellent phase-stability up to 1300℃.

关 键 词：稀土钽酸盐 声子散射 热物理性能 热障涂层 热导率 

分 类 号：TQ174.1[化学工程—陶瓷工业]