Influence of pH on rheological properties of Al2O3 slips

Slip-casting is commonly used to produce complex-shaped ceramic components. Various commercial powders have been used, characterised with respect to morphology, particle-size distribution and specific surface area. Alumina slips with 80% solid content were prepared with distilled water and ethanol as dispersing agent, with and without deflocculant. HCl and C4H13NO (tetramethylammonium hydroxide) were used for controlling the pH. Rheology, i.e. the dependence of viscosity and shear stress on shear rate, was investigated. The slip, green and sedimentation bulk densities were measured. 19 refs.