摘要
利用高能球磨固相反应法制备了(Gd_(1-x)Yb_(x))_(2)Zr_(2)O_(7)(x=0,0.1)陶瓷材料,分别采用X射线衍射仪、场发射扫描电子显微镜、阿基米德原理、热膨胀仪和激光导热仪表征了(Gd_(1-x)Yb_(x))_(2)Zr_(2)O_(7)(x=0,0.1)陶瓷材料的物相结构、微观形貌、体积密度、热膨胀系数和热扩散系数。结果表明:Gd_(2)Zr_(2)O_(7)陶瓷材料为立方烧绿石结构,(Gd_(0.9)Yb_(0.1))_(2)Zr_(2)O_(7)陶瓷材料形成了缺陷型萤石结构,均无杂相存在,Yb_(2)O_(3)的掺杂降低了Gd_(2)Zr_(2)O_(7)的晶胞参数;(Gd_(1-x)Yb_(x))_(2)Zr_(2)O_(7)(x=0,0.1)陶瓷材料的晶粒尺寸约为2μm,晶界清晰,陶瓷材料致密,孔隙率低于1.5%;(Gd_(1-x)Yb_(x))_(2)Zr_(2)O_(7)(x=0,0.1)陶瓷材料的平均热膨胀系数接近,分别为11.05×10^(-6)和10.83×10^(-6)K^(-1)。室温~600℃,Yb_(2)O_(3)的掺杂有效降低了Gd_(2)Zr_(2)O_(7)陶瓷材料的热扩散系数和热导率,但在600℃以上,Gd_(2)Zr_(2)O_(7)和(Gd_(0.9)Yb_(0.1))_(2)Zr_(2)O_(7)陶瓷材料的热扩散系数和热导率接近。
The(Gd_(1-x)Yb_(x))_(2)Zr_(2)O_(7)(x=0,0.1)ceramics were synthesized by a high energy ball milling solid reac⁃tion method.The phase structures,microstructures,bulk densities,thermal expansion coefficients and thermal diffusivities were identified by X-ray diffraction(XRD),field emission scanning electron microscope(FE-SEM),Archimedes principle,high-temperature dilatometer and laser-flash apparatus(LFA),respectively.The results indicated that Gd_(2)Zr_(2)O_(7)ceramic sintered at 1600℃for 6 h was composed of the pure pyrochlore struc⁃ture,while(Gd_(0.9)Yb_(0.1))_(2)Zr_(2)O_(7)ceramic was consisted of defective fluorite phase.In addition,the partial substitu⁃tion of Yb^(3+)for Gd^(3+)resulted in a decreased lattice parameter.The grain boundaries of the(Gd_(1-x)Yb_(x))_(2)Zr_(2)O_(7)(x=0,0.1)ceramics were clean,the size of grains was about 2μm,the sintered ceramics were dense and the porosity was less than 1.5%.The average thermal expansion coefficients of(Gd_(1-x)Yb_(x))_(2)Zr_(2)O_(7)(x=0,0.1)ceramics were simi⁃lar,which was 11.05×10^(-6)and 10.83×10^(-6)K-1,respectively.Yb^(3+)doping substantially reduced the thermal diffu⁃sivity and thermal conductivity of Gd_(2)Zr_(2)O_(7)ceramic between room temperature and 600℃,while the thermal dif⁃fusivity and thermal conductivity of Gd_(2)Zr_(2)O_(7)and(Gd_(0.9)Yb_(0.1))_(2)Zr_(2)O_(7)ceramics were similar above 600℃.
作者
张永和
谢敏
牟仁德
宋希文
王志刚
包金小
Zhang Yonghe;Xie Min;Mu Rende;Song Xiwen;Wang Zhigang;Bao Jinxiao(School of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,China;Beijing Institute of Aeronautial Materials,Beijing 100095,China)
出处
《中国稀土学报》
EI
CAS
CSCD
北大核心
2022年第2期244-249,共6页
Journal of the Chinese Society of Rare Earths
基金
国家自然科学基金项目(51762036)资助。
关键词
热障涂层陶瓷材料
锆酸钆
物相结构
热物理性能
ceramic materials for thermal barrier coatings
Gd2Zr2O7
phase structure
thermophysical properties