Application of the High-Temperature X-Ray Diffraction Method to the Diffusion Study in the MgO-Al_2O_3 System

摘要

A mathematical model has been developed to study the kinetics of formation of spinel (MgAl_2O_4) using the high-temperature X-ray diffraction method. Experiments have been carried out for the MgO-Al_2O_3 system on an X-ray diffractometer in the temperature range of 1373 to 1673 K. Equi-molar mixtures of MgO and Al_2O_3 powders have been employed as the starting samples. The interdiffusivity values calculated from the high-temperature X-ray diffraction data using the present model are in good agreement with those obtained by diffusion couple experiments. The activation energy for the interdiffusion process has been found to be 354.2 kJ/mol in the temperature range 1473 to 1873 K.