Influence of Nb2O5 additive on the densification and microstructural evolution of fine alumina powders

The effect of Nb2O5 additive on the densification and microstructural evolution of fine alumina powders has been investigated. The dopant concentration added ranged from 0.5 to 2.0 mol%. It was observed that the doping of Nb2O5 improved the densification of alumina. Besides, the sintering temperature could be lowered about 100-150 °C by doping a small amount of Nb2O5 for sintering at the same period. In addition, the Nb2O5 dopant promoted the grain growth of alumina and second-phase AlNbO4 particles were generated in the doped samples.