고온 X-선 회절 방법으로 0.05 w/o TiO$_2$첨가로 인한 $UO_2$활성화 소결기구에 미치는 영 향을 조사하였다. 120$0^{circ}C$에서 TiO$_2$를 첨가한 $UO_2$와 첨가하지 않은 $UO_2$격자상수의 열팽창은 상온에서의 격자상수 보다 각각 1.448%와 1.354% 더 컸으며 TiO$_2$를 첨가한 경우가 약0.094% 더 컸었다. 또한 0.05 w/o TiO$_2$를 첨가한 $UO_2$Pellet의 108$0^{circ}C$에서의 격자상수는 120$0^{circ}C$에서의 $UO_2$격자상수와 동일하였다. 이 온도차이는 $UO_2$소결시 0.05w/o TiO$_2$의 첨가로 인하여 강하된 소결온도와 잘 일치된다. 이와같이 TiO$_2$의 미량첨가가 고온에서 $UO_2$격자상수의 열팽창을 증가시켜 $UO_2$의 화산을 촉진시킴으로서 활성화 소결에 영향을 준다고 생각된다.
The mechanism for activated sintering of UO$_2$by an addition of 0.05 w/o TiO$_2$was investigated using a high temperature X-ray diffractometer. The diffraction pattern of UO$_2$pellets was studied in a temperature range from room temperature to 120$0^{circ}C$ in hydrogen atmosphere. At 120$0^{circ}C$, the expansion of UO$_2$lattice were 1.448% and 1.354% greater when it was compared with those at room temperature for pellets with and without the 0.05 w/o TiO$_2$addition, respectively-The effect of the TiO$_2$addition is to increase the lattice constant of UO$_2$by 0.094% at 120$0^{circ}C$. The lattice constant at 120$0^{circ}C$without the TiO$_2$addition is equal to that at 108$0^{circ}C$ with the 0.05 w/o TiO$_2$addition. This temperature difference could be well compared with the suppression of sintering temperature by TiO$_2$hat had been observed Previously. It is believed that the increase in lattice expansion due to the TiO$_2$addition would give rise to the activated sintering of UO$_2$by the lattice-expansion-induced-enhancement of self diffusion.
