Freeze casting of porous materials: review of critical factors in microstructure evolution

Abstract

Freeze casting is a promising technique to fabricate porous materials with complex pore shapes and component geometries. This review is aimed to elaborate the fundamental principles of the porous microstructure evolution and critical factors that influence the fundamental physics involved in freeze casting of particulate suspensions. The discussion separately analyses homogeneous and directional freeze casting for both aqueous and non-aqueous systems. The effects of additives, freezing conditions, suspension solids loading and particle size on pore shape, size and morphology evolution are discussed. Special techniques based on modified freeze casting, such as freeze tape casting, double sided freeze casting and field directed freeze casting, are also included.