Ce_(0.8)Y_(0.2)O_(1.9)氧化物的烧结及晶粒生长动力学研究

通过对Ce0.8Y0.2O1.9(YDC)素坯烧结行为的考察,得到了试样的密度、晶粒大小随烧结温度(1000~1500℃)的变化规律。利用扫描电子显微镜对烧结体的晶粒尺寸分布进行统计分析表明:Ce0.8Y0.2O1.9晶粒生长在两个烧结温度区域内分别遵循不同的速率方程,在1000~1300℃较低的温度范围内,晶粒成长的活化能较小(171.1 kJ/mol),即烧结温度对晶粒成长的影响较小;在1300~1500℃较高的温度范围,晶粒生长的活化能较大(479.8 kJ/mol),即晶粒成长对烧结温度的高低表现为非常敏感,并且晶粒尺寸分布显著宽化。烧结体的密度在1000~1400℃范围内随温度的升高几乎直线上升,在1400℃时相对密度达98.5%,1400℃以上则提高的幅度变得很小。

Study of Sintering and Grain-growth Kinetics for Ce0.8Y0.2O1.9 Oxide

The dependenre of the density and grain size of Ce_(0.8)Y_(0.2)O_(1.9) on sintering temperature(1000～1500℃ was studied. Statistical analysis of grain size by SEM observation suggested that the grain growth of Ce_(0.8)Y_(0.2)O_(1.9) followed different kinetic equations when sintered at two different temperature ranges. At inv temperature range of 1000～1300 ℃ , the activation energy of grain growth was relative small(171. 1 kJ/mol) , indicating a weak effect of temperature on the grain size. However, at high temperature range of 1300～1500 ℃, the activation energy became large (479. 8 kJ/mol), indicating the grain growth was sensitive to the sintering temperature. The dispersion of the distribution of grain size also became evident. The relative density of the sintered body increased fast with increasing temperature and reached 98. 5% at 1400 ℃. Then, it increased gradually at temperature above 1400 ℃.