Effects of α-Al_2O_3 Seeds on the Phase Transformation and Microstructure of Alumina

Nanometer NH4Al(OH)2CO3 precursor was synthesized from NH4Al(SO4)2 and NH4HCO3. The effect of α-Al2O3 seeds (-150nm) on the phase transformation and micrograph of alumina was studied. The results show that under the conditions of adding a small quantity of α-Al2O3 seeds, the nucleating temperature can be lowered, the transition rate enhanced effectivelly, the transition of Al2O3 from θ to α phase can be completed at a lower temperature, and the grain accumulation can also be influnced to a certain extent.