Shear Thinning and Thickening of Alumina Suspensions

The rheological behavior of alumina suspension stabilized with Tri-ammonia citrate (TAC) was studied. It was thought that there would form some particle clusters due to the collisions between particles caused by their relative motion in the suspension, and such particle clusters are classified as thermodynamic clusters and hydrodynamic clusters by their origin. Shear thinning is the result of decomposition of the thermodynamic clusters, while shear thickening is the result of formation of the hydrodynamic clusters. From the view of cluster-forming potential barrier, it was deemed that the viscosities of alumina suspensions at low and high shear rates are respectively determined by zeta potential and Stern potential on the particle surface, and shear thickening behavior can be suppressed with some excessive TAC.