Processing of porous cordierite bodies by starch consolidation

Porous cordierite ceramics, formed from a mixture of ball clay, talc, alumina, and silica sand, were developed by a new direct consolidation method based on the properties of starch in water. The gelling capability of starch granules in warm water allows the transformation of a stable suspension into a rigid and stiff body that can be machined in the green state. Starch consolidation can be performed in nonporous molds, enabling materials with controlled porosity to be obtained by varying the starch content in the slip composition. The simplicity of the process as well as the low price of starches makes this new consolidation technique very promising from an industrial point of view. The results showed good agreement with the expected porosities of the cordierite sintered bodies, thus enabling the design of porous textures and tailoring of the material to applications.