水热法制备纳米氧化锆煅烧过程中晶粒生长特性研究

Grain Growth Characteristics of Hydrothermally Prepared Yttria Stabilized Zirconia Nanocrystals during Calcination

摘要:

对水热法制备的纳米氧化锆在不同温度和保温时间条件下进行了煅烧，采用X射线结合全谱模型方法分析了晶粒尺寸和晶粒尺寸分布的变化。结果表明，当煅烧温度在300℃时，纳米氧化锆晶粒开始生长并伴随着晶粒尺寸分布宽化。纳米氧化锆的晶粒生长速率及晶粒尺寸分布与煅烧温度和保温时间有关。根据分析结果，计算了晶粒生长指数和晶粒生长活化能。讨论了晶粒生长机理，晶粒旋转合并是纳米氧化锆晶粒生长的主要方式。

Abstract:

Yttria stabilized zirconia (YSZ) nanocrystals were prepared by hydrothermal synthesis and were calcinated at different temperatures and with different isothermal hold time. X-ray diffraction via whole powder pattern modeling approach is used to study the grain growth as well as the evolution of grain size distribution of YSZ nanocrystals. Results show that YSZ nanocrystals start to grow along with the grain size distribution broadening at temperature about 300℃. The grain growth rate and the grain size distribution of YSZ nanocrystals are dependent on the calcination temperature and the isothermal hold time. The grain growth exponent and the active energy of grain growth were calculated. Grain rotation induced grain coalescence is suggested as the predominant way of grain growth of YSZ nanocrystals.