Using Al(NO3)3·9H2O

Cu(NO3)2·3H2O and Ti(OC4H9)4 as raw materials

Al2O3 submicron powders were synthesized at a low temperature by the sol-gel process

and the phase and microstructure of powders were investigated.By doping Cu(NO3)2·3H2O and Ti(OC4H9)4 into alumina sol

a blue gel was obtained through placing the sol at 80℃ for a long time.Calcining the blue gel at 950℃ for 2 h produced amorphous Al2O3 powder with only a little γ-Al2O3 crystal phase

while α-Al2O3 nanopowders with a diameter of 80—100 nm were formed at the calcining temperature of 1000℃.As the calcining temperature increased to 1050℃

the grains grew to 200—400 nm.These results indicated that the synthesis temperature of α