Permeability and structure of cellular ceramics: A comparison between two preparation techniques

This work presents a comparative study of structural and aerodynamic proper ties of cellular ceramics prepared by two different techniques: the ceramic replication of an organic substrate and the gelcasting of foams. Permeabil ity constants calculated from Ergun's equation were related to their appare nt porosity and pore size. The technique of gelcasting of foams yielded str uctures as porous as the replication technique does, but with smaller pores and a fully densified strut. This type of structure ensures a higher mecha nical strength without a significant decrease in the permeability.