Synthesis and densification behaviour of magnesium aluminate spinel: Effect of Dy2O3

Magnesium aluminate spinels have been developed by reaction sintering of calcined alumina and calcined magnesia and its densification behaviour was studied in presence of Dy2O3. Green bar made from stoichiometric spinel composition with and without Dy2O3 were subjected to dilatometric study, densification study and microstructural evaluation by SEM. It was found that Dy2O3 additive does not have significant effect on the spinelisation but favours the densification of the spinel. Microstructure of sintered spinel without any additive is non-uniform with some exaggerated grain growth. Dy2O3 prevents the exaggerated grain growth and thereby helps in the densification process.