Effect of the addition of sintering aid on densification behaviour of alumina ceramic

Alumina ceramic densified using microwave sintering (2.45 GHz, 2800 W) process at temperature of 1500℃ for 1 h. The consolidation of alumina particles (≈2 µm) was assisted by MgO and TiO2 additives in various proportions. The influence of MgO and TiO2 additives on densification mechanism and physical property of alumina has been studied. It has been observed that the density attained a maximum value of 3.95 g/cm3 for sample doped with MgO (0.25 vol %) and TiO2 (0.25 vol %). The microstructure study and microhardness results reveal that the addition of optimum amount of doping i.e. 0.25 vol % MgO and 0.25 vol % TiO2 is the feasible way to improve the densification of alumina and physical properties.