Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5437345 | Ceramics International | 2017 | 16 Pages |
Abstract
Porous Si3N4 ceramics were fabricated via incomplete gelcasting and freeze-drying method followed by pressureless sintering at 1690Â â. The specific way used in this work was to slow down the gelling process of ceramic suspensions by stopping water evaporation. Since water was retained and further frozen before the suspensions were totally gelled in normal way, pore structure was modified. Compared to direct freeze-casting, the polymer framework generated by polymerization of organic components prevented ice crystals from growing to large sizes. Performance of porous ceramics can also be controlled by the gelling time. Further on, porous Si3N4 ceramics with controlled pore structures can be obtained without using other organic additives. The gelling agent used in this study is a copolymer of isobutylene and maleic anhydride (IBMA). The small addition amount was only 0.2Â wt%, but could greatly change the microstructure as well as mechanical performance of porous ceramics.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Feng Wang, Hao Gu, Jinwei Yin, Dongxu Yao, Yongfeng Xia, Kaihui Zuo, Hanqin Liang, Congqin Ning, YuPing Zeng,