Ice templating of ZrB2 porous architectures

For the first time, freeze casting of aqueous ZrB2 based suspension was performed in order to produce porous architectures with main unidirectional anisotropic pores interconnected by diffuse globular-isotropic pores. The porosity characterizing the green bodies after the sublimation process is the replica of the ice crystals. The effects of solid content, suspension stabilization and cold transmission depending on mold type were studied since micro and macrostructure and, hence, the properties of the sintered body are determined by controlling the growth direction of the ice crystals during freezing. Improved mechanical performances are obtained by changing the above mentioned parameters, in virtue of the formation of thinner and more homogenously distributed ceramic lamellae. Possible applications of these materials include high temperature porous volumetric absorbers for concentrating solar power systems.