Particle growth characteristics of MgO

The particle growth characteristics of active MgO in the size range 70-400 Å have been studied by the x-ray line broadening technique. The starting material was a synthetic magnesium hydroxide, which was decomposed and then heat treated under isothermal conditions in the temperature range 400-900° C in vacuum and in H₂O vapor. The particle growth rate was very much higher in vapor than that in vacuum. The results were analysed by the conventional grain growth equation, Dn=Kt and newly developed models. In these models, surface diffusion, bulk diffusion and evaporation-condensation have been considered for mass transport mechanisms. The activation energy for the particle growth process of MgO in H₂O vapor was calculated to be about 31 Kcal/mole.Applied Science, Faculty ofMaterials Engineering, Department ofGraduat