Effect of suspension state on the pore structure of freeze-cast ceramics

The forming process of a freeze-cast pore structure and the packing state of ceramic particles have been studied from a colloid point of view. Several typical alumina suspensions with different dispersion states are prepared by controlling the dispersant amount and the pH value. Microstructures of the samples freeze-cast and sintered from the suspension were observed. It is found that the interaction states of the particles in suspension have a dramatic influence on both the packing state in the dense region and the structures of channels. The results also indicate that the short-range interactions among the particles are a crucial factor for the pore structure.