RHEOLOGY OF STERICALLY STABILIZED CERAMIC SUSPENSIONS

The shear viscosity and dynamic mechanical properties of sterically stabilized alumina-in-paraffin oil suspensions were measured using a cone and plate viscometer. Solid volume fraction, amount of polymeric dispersant, temperature, and deformation rate were varied in a systematic manner. Results, cast in dimensionless form, were compared with expected values for model suspensions of monodisperse spheres. Viscosity curves characterized by an upper and lower Newtonian region with an intermediate shear thinning region were obtained, and these were independent of the medium viscosity and temperature. Thus the behavior of the real suspensions was similar to that of the model suspensions. However, the limiting shear rate viscosities were higher in the former case as compared to the latter.