Effect of alumina reactivity on the densification of reaction sintered nonstoichiometric spinels

Densification of two different nonstoichiometric spinels (Al2O3 content 66 wt.% and 90 wt.%) was studied by using the reaction sintering technique. Sintered sea water magnesia and commercial alumina were used as starting materials. Reactivity of alumina was changed by calcinations between 800 and 1600 °C. Sintering for all the batches was carried out in the temperature range of 1600 and 1700 °C. Sintered products were characterized by bulk density, phase analysis and microstructure. Alumina calcined at 1200 °C was found to be optimum for densification of non-stoichiometric spinels.