Fabrication and characterization of porous CaSiO3 ceramics

Porous CaSiO₃ ceramics were prepared via a solid-state reaction method using CaCO₃ and SiO₂ as raw materials and active carbon as a pore-forming agent. The results indicated that porous CaSiO₃ ceramics could be obtained under a low sintering temperature of 1320?°C. The addition of active carbon significantly affected the volume density, microstructure, pore size distribution and mechanical strength of porous CaSiO₃ ceramics. With the increase of active carbon content, the volume density decreased, meanwhile the pore size and porosity increased gradually. Besides, the three-point bending tests demonstrated that the mechanical strength was decreased with increasing active carbon content. However, all the porous ceramics still exhibited high mechanical strength. These results implied that the increase of active carbon content not only enlarged the pore size and enhanced the porosity, but also kept a remarkable mechanical strength of porous CaSiO₃ ceramics. Therefore, these rationally designed CaSiO₃ porous ceramics will be a highly potential material in various applications due to its high mechanical strength, low sintering temperature and narrow pore size distribution.