离心成型技术制备孔梯度分布的氧化锆多孔陶瓷

以2种粒径分布不同的ZrO_2微粉为原料,利用离心成型技术制备孔梯度分布的ZrO_2多孔陶瓷.测量了ZrO_2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ZrO_2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,ZrO_2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,ZrO_2颗粒的分离现象明显,孔隙呈梯度分布.40%(体积分数)固含量ZrO_2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.

Preparation of ZrO2 Porous Ceramics with Gradient Pore Distribution by Centrifugal Slip Casting

ZrO_2 porous ceramics with gradient pore distribution are prepared by centrifugal slip casting method using two kinds of ZrO_2 powders with different particle size.Zeta potentials of ZrO_2 particles at different pH values are measured.The effect of centrifugal acceleration and solid loading of slurries on segregation of ZrO_2 panicles is studied,and microstructure,porosity and pore size of sintered products are observed.The results show Zeta potential of ZrO_2 particles is highest at pH=10 and the slurries are better dispersed.At low solid content and high centrifugal acceleration,the segregation phenomenon of ZrO_2 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 are15.2%and below 0.3μm,respectively.