Slip casting of cordierite and cordierite mullite materials

The obtention of cordierite and cordierite-mullite ceramics by slip casting is studied. Aqueous slips with solids contents up to 65 wt% were used. The effect of the deflocculant content and the mixing time on the rheological behavior was studied, showing always a shear thickening behavior, which can be deletereous for demolding and handling. The rheological behavior became Newtonian by reducing the solid content up to 60 wt% and adding a plastici zer. This led to higher green densities (near 63% th). Different firing cyc les were tested to improve the sintered density, reaching values between 96 .5 and 97.5% th. In all cases, both the green and the sintered densities we re significantly higher than those obtained by axial pressing. (C) 1998 Els evier Science Limited. All rights reserved.