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 capabi lity of starch granules in warm water allows the transformation of a s table suspension into a rigid and stiff body that can be machined in t he green state. Starch consolidation can be performed in nonporous mol ds, enabling materials with controlled porosity to be obtained by vary ing the starch content in the slip composition. The simplicity of the process as well as the low price of starches makes this new consolidat ion technique very promising from an industrial point of view. The res ults showed good agreement with the expected porosities of the cordier ite sintered bodies, thus enabling the design of porous textures and t ailoring of the material to applications. (C) 1998 Elsevier Science Lt d.