Abstract:

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