Abstract:The densification and microstructure of different spinelized magnesium aluminate spinels (MAS) were studied adding Sc₂O₃ as additive. Sintered products were then characterized in terms of densification, phase analysis, quantitative elemental analysis and microstructure. The results show thatSc₂O₃ is found to be beneficial for the densification of MAS. Sc₂O₃ has a more significant effect on the densification of partially spinelized MAS batch than that of fully spinelized MAS batch. At the sintering temperature of 1650 °C, the bulk density of sintered products of partially spinelized powders increases by 0.243 g/cm³ as the Sc₂O₃ content increases from 0 to 4% (mass fraction) and that of fully spinelized powder increases by 0.14 g/cm³. Compared with the sintered samples prepared from the fully spinelized powder, the sintered samples using the partially spinelized powders as raw materials have more compact microstructures.

Key words: magnesium aluminate spinel; Sc₂O₃; densification; microstructure; elemental analysis