(Sm_(0.5)Nd_(0.5))_(3)Ce_(7)Ta_(2)O_(23.5)和(Yb_(0.5)Dy_(0.5))_(3)Ce_(7)Ta_(2)O_(23.5)氧化物的热物理性能  

ThermophysicalPerformancesof(Sm_(0.5)Nd_(0.5))_(3)Ce_(7)Ta_(2)O_(23.5)and(Yb_(0.5)Dy_(0.5))_(3)Ce_(7)Ta_(2)O_(23.5)Oxides

作　　者：冉书明[1] 郭怡 RAN Shuming;GUO Yi(School of Inelligent Manufacturing,Chongqing Water Resources and Elctrical 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：《机械工程材料》2022年第6期21-25,30,共6页Materials For Mechanical Engineering

基　　金：重庆市教科委科学技术研究项目(KJZD-K201903801)。

摘　　要：以高纯度Sm_(2)O_(3)、Nd O_(3)、Dy_(2)O_(3)、Yb_(2)O_(3)、Ce O_(2)和Ta_(2)O_5为原材料,采用多步高温固相烧结法制备了(Sm_(0.5)Nd_(0.5))_(3)Ce_(7)Ta_(2)O_(23.5)和(Yb_(0.5)Dy_(0.5))_(3)Ce_(7)Ta_(2)O_(23.5)氧化物,研究了其晶体结构、微观形貌、热物理性能等。结果表明:制备的氧化物均具有单一的萤石结构,其结构致密,晶界清晰,元素种类和原子比与化学式基本一致;这2种氧化物的热导率明显低于7YSZ,且(Yb_(0.5)Dy_(0.5))_(3)Ce_(7)Ta_(2)O_(23.5)的热导率低于(Sm_(0.5)Nd_(0.5))_(3)Ce_(7)Ta_(2)O_(23.5)的;(Yb_(0.5)Dy_(0.5))_(3)Ce_(7)Ta_(2)O_(23.5)在900℃以上高温热膨胀系数略高于(Sm_(0.5)Nd_(0.5))_(3)Ce_(7)Ta_(2)O_(23.5),二者在1200℃时的热膨胀系数分别是12.2×10^(-6,)12.5×10^(-6)K^(-1,)均大于7YSZ的9×10^(-6)K^(-1);2种氧化物的热导率和热膨胀系数均满足热障涂层的要求。Taking Sm_(2)O_(3),NdO_(3),Dy_(2)O_(3),Yb2O_(3),CeO_(2)and Ta_(2)O_(5)with high purity as raw materials,(Sm_(0.5)Nd_(0.5))_(3)Ce_(7)Ta_(2)O_(23.5)and(Yb_(0.5)Dy_(0.5))_(3)Ce_(7)Ta_(2)O_(23.5)oxides were synthesized by multi-step solid phase sintering at high temperature,and the crystalline structure,micromorphology and thermophysical properties were investigated.The results show that obtained oxides exhibited single fluorite structure.The microstructure was dense,and the interfaces among grains were very clean.The element composition and the atom ratio were consistent with the chemical formula.The thermal conductivity of the two oxides was obviously lower than that of 7YSZ,and the thermal conductivity of(Yb_(0.5)Dy_(0.5))_(3)Ce_(7)Ta_(2)O_(23.5)was lower than that of(Sm_(0.5)Nd_(0.5))_(3)Ce_(7)Ta_(2)O_(23.5).The thermal expansion coefficient above 900℃of(Yb_(0.5)Dy_(0.5))_(3)Ce_(7)Ta_(2)O_(23.5)was slightly higher than that of(Sm_(0.5)Nd_(0.5))_(3)Ce_(7)Ta_(2)O_(23.5),and thermal expansion coefficients at 1200℃of two oxides were 12.2×10-6,12.5×10^(-6)K^(-1),respectively,which were much higher than 9×10^(-6)K^(-1)of 7YSZ.The thermal conductivity and expansion coefficient of the two oxides satisfied the requirements for thermal barrier coatings.

关 键 词：热障涂层 热导率 热膨胀系数 晶体结构 

分 类 号：TG174.442[金属学及工艺—金属表面处理]