Surface-diffusion studies on UO2 and MgO

摘要: An optical interferometric technique has been used to study the growth of grain boundary grooves and decay surface scratches on UO2 MgO at temperatures in range 1100 1700° C. The results were interpreted using equations derived by W. Mullins it was found that surface-diffusion predominant material transport process for both oxides under experimental conditions used. Surface-diffusion coefficients activation energies calculated, gave following variation mass transfer coefficientDs with temperature. $$\begin{gathered} UO_{2.005, } {\text{ }}D_s = 1.3 x 10^8 exp^{ - 11000 \pm 15000} /RT[1200{\text{ }}1{\text{400}}^\circ C]}} \hfill \\ MgO, D_s 8 10^4 88500 }}15{\text{00}}^\circ \end{gathered}$$