Jc. Chang et al., PRESSURE SENSITIVITY FOR PARTICLE PACKING OF AQUEOUS AL2O3 SLURRIES VS INTERPARTICLE POTENTIAL, Journal of the American Ceramic Society, 77(5), 1994, pp. 1357-1360
The relation between relative density and applied network pressure has
been determined for aqueous Al2O3 slurries prepared with different in
terparticle potentials and consolidated by centrifugation. Attractive
interparticle potentials were obtained by either changing the pH to th
e isoelectric point or adding an excess electrolyte. A range of centri
fugal speeds produced consolidation pressures between 10(-3) and 10 MP
a. At lower speeds, the density gradient was determined with an X-ray
absorption technique. The maximum packing density (0.62 +/- 0.02) was
achieved for both dispersed and coagulated slurries at network pressur
es >0.5 MPa. At lower pressures, the packing density of these slurries
was pressure-dependent, where the coagulated (salt added) slurries ha
d a relative density between that of the dispersed and flocced slurrie
s. Slurries flocculated by adjusting the pH to the isoelectric point n
ever reached the highest packing density at the largest pressure.