Influence of ambient temperature on the rheological properties of alumina tape casting slurry

Abstract

Pseudoplasticity and viscosity of slurries are two important characteristics which are always monitored to get good and reproducable tape-cast samples. Though it is known that the viscosity of solvents changes with temperature, no work has so far been done to study the viscosity of standard tape casting slurries with ambient temperature (which shows seasonal variation), excepting a few reports on slurries containing powder and dispersant only. In the present work, it has been observed that ambient temperature has a significant effect on the viscosity and shear rate exponent of a typical tape casting slurry containing powder, dispersant, binder and plasticizer. Though the dispersant and plasticizer have important roles to modify the viscosity and shear rate exponent of a tape casting slurry, the binder plays the key role to exhibit the temperature dependence of viscosity and shear rate exponent of the tape casting slurry. The roles of binder, plasticizer and dispersants have been studied to explain the slurry characteristics with temperature. From the present study it can be inferred that the influence of ambient temperature during tape casting should be taken into account to get truly reproducible tape-cast samples.