以2种粒径分布不同的ZrO2微粉为原料,利用离心成型技术制备孔梯度分布的ZrO2多孔陶瓷。测量了ZrO2颗粒在不同pH值下的Zeta电位,研究了离心加速度和浆料固相含量对ZrO2颗粒分离现象的影响,观察了烧结产物的微观形貌、孔隙度以及孔径分布。研究结果表明,在pH=10时,ZrO2颗粒的Zeta电位最高,浆料具有良好的分散性。在较低的固相含量和较高的离心加速度下,ZrO2颗粒的分离现明显,孔隙呈梯度分布。40%(体积分数)固含量ZrO2浆料离心所得样品在1400℃烧结3h后,孔隙呈现良好的梯度分布,其底部孔隙度为24.6%,气孔尺寸在1~3μm之间;顶部孔隙度为15.2%,气孔尺寸大多在0.3μm以下。
ZrO2 porous ceramics with gradient pore distribution are prepared by centrifugal slip casting method using two kinds of ZrO2 powders with different particle size. Zeta potentials of ZrO2 particles at different pH values are measured. The effect of centrifugal acceleration and solid loading of slurries on segregation of ZrO2 particles is studied, and microstructure, porosity and pore size of sintered products are observed. The results show Zeta potential of ZrO2 particles is highest at pH=10 and the slurries are better dispersed. At low solid content and high centrifugal acceleration, the segregation phenomenon of ZrO2 particles becomes obvious, which results in the formation of gradient pore. After sintered at 1400℃ for 3h, the porosity and pore size of the bottom of the samples prepared with 40vol% slurries are 24. 6% and about 1 -3μm, respectively. The porosity and pore size of top of the samples are 15.2% and below 0. 3μm, respectively.