Yang Zhihong, Chen Nan, Qin Xiaomei
School of Materials Science and Engineering, Nanchang University, Nanchang 330031, China.
Department of Physics, Shanghai Normal University, Shanghai 200234, China.
Materials (Basel). 2018 Sep 19;11(9):1784. doi: 10.3390/ma11091784.
The gelcasting method is usually employed to fabricate relatively dense ceramics. In this work, however, porous Al₂O₃ ceramics with submicron-sized pores were fabricated using the water-based gelcasting method by keeping the Al₂O₃ content at low levels. By controlling the water content in the ceramic slurries and the sintering temperature of the green samples, the volume fractions and the size characteristics of the pores in the porous Al₂O₃ can be readily obtained. For the porous Al₂O₃ ceramics prepared with 30 vol.% Al₂O₃ content in the slurries, their open porosities were from 38.3% to 47.2%, while their median pore sizes varied from 299.8 nm to 371.9 nm. When there was more Al₂O₃ content in the slurries (40 vol.% Al₂O₃), the porous Al₂O₃ ceramics had open porosities from 37.0% to 46.5%, and median pore sizes from 355.4 nm to 363.1 nm. It was found that a higher sintering temperature and Al₂O₃ content in the slurries increased the mechanical strength of the porous Al₂O₃ ceramics.
凝胶注模法通常用于制备相对致密的陶瓷。然而，在本研究中，通过将Al₂O₃含量保持在较低水平，采用水基凝胶注模法制备了具有亚微米级孔隙的多孔Al₂O₃陶瓷。通过控制陶瓷浆料中的含水量和生坯样品的烧结温度，可以很容易地获得多孔Al₂O₃中孔隙的体积分数和尺寸特征。对于浆料中Al₂O₃含量为30 vol.%制备的多孔Al₂O₃陶瓷，其开孔率为38.3%至47.2%，而其平均孔径在299.8 nm至371.9 nm之间变化。当浆料中Al₂O₃含量更高（40 vol.% Al₂O₃）时，多孔Al₂O₃陶瓷的开孔率为37.0%至46.5%，平均孔径为355.4 nm至363.1 nm。研究发现，较高的烧结温度和浆料中Al₂O₃含量提高了多孔Al₂O₃陶瓷的机械强度。
