A facile approach for preparing Al₂O₃ reticulated porous ceramics with optimized closed-cell struts and excellent mechanical properties

Reticulated porous ceramics (RPCs) are of great value in applications such as non-ferrous alloys and flue gas filtration. For the purpose of further enhancing the mechanical properties of RPCs without drastically reducing their apparent porosity, a new route to improve the mechanical properties of the strut by constructing a closed-cell structure was proposed to fabricate Al₂O₃ reticulated porous ceramics (ARPCs). The effects of cryolite on the generation of closed pores, the microstructure, and the mechanical performance of struts were investigated. It was found that the addition of cryolite promoted the densification of the pore walls within the struts during sintering. Furthermore, ARPCs added with 10 wt% cryolite achieved an apparent porosity of nearly 80%, while exhibiting excellent mechanical strength and thermal-shock resistance, with compressive strength and residual strength ratio significantly increased by 56% and 11%, respectively, compared to the samples without cryolite addition.