ZrO 2 powders and ceramics doped with Y 2O 3 and Al 2O 3 respectively were prepared by a coprecipitation-gel method using low temperature calcining and medium temperature sintering. The structure stability and sintering properties of ZrO 2 phase doped with the different oxides were studied by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results show that calcined at 870°C for 15 min, ZrO 2 powders doped with Y 2O 3 of 5% in molar fraction have a cubic phase, but those doped with Al 2O 3 of 5% in molar fraction have a tetragonal phase. After sintering the formed powders at 1400°C for 4 h, the former remains the cubic phase at room temperature, but the latter has a monoclinic phase. In the calcining powders, Al 3+ dissolves into the lattice of ZrO 2 and stabilizes the ZrO 2 tetragonal lattice; whereas in their ceramic, Al 3+ diffuses from the ZrO 2 lattice to the grain boundaries, so it can not afford a stabilizing effect on the ZrO 2, only plays a role in promoting the sintering and thinning grain.
|ジャーナル||Beijing Keji Daxue Xuebao/Journal of University of Science and Technology Beijing|
|出版ステータス||出版済み - 3 2012|
All Science Journal Classification (ASJC) codes