Effect of the processing conditions of reticulated porous alumina on the compressive strength

Reticulated porous ceramics feature a three-dimensional network structure with high porosity and permeability simultaneously. However, generally, the compressive strength capabilities of reticulated porous ceramics are low, which severely limits applications of these materials. To increase the compressive strength of reticulated porous ceramics, it is necessary to coat the strut walls of the polyurethane foam completely with alumina slurry to form a thin ceramic coating layer after optimizing the processing conditions, specifically the alumina slurry composition and the coating condition. Although it remains challenging to improve the compressive strength of reticulated porous ceramics, thus far efforts to do so are underreported. Therefore, in this study, we attempt to optimize the composition (thickener, dispersant, and binder) of the alumina slurry. Among various types of reticulated porous ceramics, we focus on reticulated porous alumina here. Although there are numerous studies regarding porous alumina, which is already widely used, investigations of reticulated porous alumina are rare. In this study, we determined the optimized processing conditions to improve the compressive strength of reticulated porous alumina. These conditions, specifically the composition of the alumina slurry and the pore density of the polyurethane foam, are discussed.