Preparation of Reticulated Porous Ceramics with a Controlled Pore Structure

A polymeric sponge with interconnected pores in all three dimensions was chosen to prepare firstly the reticulated preform by the replication process. After the polymeric sponge was burned out, the reticulated preform was presintered to obtain enough operating strength. The struts of the reticulated preform exhibit porous microstructure, which is beneficial to coating of the slurry on them. The coating treatment was conducted by the thinner slurry on the reticulated preform. The typical flaws such as longitudinal strut cracks were eliminated by recoating process; additionally, very thin struts were avoided by coating. The reticulated ceramics with a very uniform macrostructure was produced by recoating process and few filled cells were invisible. The effects of coating numbers on the pore size, strut thickness and relative density were investigated in detail. This work has developed successfully an innovative approach to precisely control the macrostructure for the reticulated ceramics, which is valuable to predict and optimize their properties such as mechanical properties and permeability.