Pa. Smith et Ra. Haber, EFFECT OF PARTICLE PACKING ON THE FILTRATION AND RHEOLOGY BEHAVIOR OFEXTENDED SIZE DISTRIBUTION ALUMINA SUSPENSIONS, Journal of the American Ceramic Society, 78(7), 1995, pp. 1737-1744
The effect of particle packing on the theology and casting behavior an
d cast cake characteristics of aqueous alumina suspensions (50 vol%) w
as investigated using the Andreasen approach, Varied packing was produ
ced by blending two starting materials that differed in average size b
y a factor of 10, Formulations closest to ideal packing lowered viscos
ity, Specifically, the lowest viscosity suspension, 196 mPa . s, was p
roduced with the distribution closest to the ideal packing distributio
n, Typically, a well-dispersed suspension (characterized by low viscos
ity) casts slower than one of poorer dispersion given the same solids
content, However, the suspension that provided the lowest viscosity ca
st at a rate of 0.41 mm(2)/s, which was the fastest rate of the compar
ed formulations, Therefore, suspensions consisting of extended size di
stributions do not necessitate slow filtration rates, The colloidal pr
operties of the individual starting materials, low shear rate theology
, and mercury porosimetry were used to explain the unexpected casting
behavior, The dispersion and structure formation within the suspension
were investigated using electrokinetic sonic amplitude measurements,
Mercury porosimetry characterized the from channels that developed in
the casts, Low shear rate theology confirmed the presence of flocculat
ion that was first suggested by the porosimetry results.