Freeze Casting

Freeze casting can be used for any powder material dispersible in a solvent. Indeed, the mechanisms responsible of formation of the structure are not dependent on the nature of the powder. Studies on polymers, metals and ceramics have confirmed this. In the case of the use of water as solvent, the production process has the advantage of being environmentally friendly with a very limited quantity of organics used. Typical structural defects were observed: the heterogeneities of the microstructure, the formation of a dense and transient zone, the pore size gradient along the height of the sample and the formation of cracks perpendicular to the freezing direction. Three main factors having a strong impact on the microstructure have been identified: freezing rate, powder content and the binder nature and content. The control of the porous structure via the experimental conditions makes it possible to develop materials for various applications.