A novel design of Al2O3-ZrO2 reticulated porous ceramics with hierarchical pore structures and excellent properties

Abstract

The use of reticulated porous ceramics(RPCs) was of great interest in high-temperature catalytic application owing to their high surface area. In order to further optimize the pore structure and mechanical properties of RPCs, vacuum infiltration with CaCO3-Al2O3 slurries process was applied to fabricate Al2O3-ZrO2 RPCs with hierarchical pore structures. The pores within ceramic struts were prepared by processes of CaCO3 decomposition and calcium hexaluminate grains growth. And the compressive residual stress was formed within multi-layered struts owing to the difference in the thermal expansion of coating layer and ceramic struts, which was established as a key factor in improving the mechanical properties and thermal shock resistance of RPCs. Furthermore, the size of pores within struts ranging from 5 μm to 14 μm affected the thermal shock resistance of RPCs significantly based on grey incidence analysis. And the potential of this materials as high-temperature catalyst supports was demonstrated.