Kinetic of initial sintering of oxide powders under controlled gaseous atmosphere
Résumé
The experimental rates of surface area are reported for TiO2 anatase, gamma Al2O3, CeO2, ZrO2 as a function of the influencing gases: H2O, O2, CO2, and HCl. From the determination of the rates at a fixed value of the surface area, the kinetic law takes a mathematical expression which involves the partial pressure of each gas raised to some power. Mechanistic models are proposed, which consist of the transport of cations and anions through a sequence of elementary steps involving point defects as the reactive speed.