Abstract
The applied pressure and suspension height during consolidation of an aqueous suspension with 800 or 30 nm SiC particles were continuously recorded using a developed pressure filtration apparatus. The suspension of 5-30 vol% solid was filtered through three sheets of a 0.1 μm pore diameter membrane filter attached to the bottom of the piston displaced at 0.05-0.5 mm/min. The dehydrated solution flowed into the pore channels in the piston in the Teflon cylinder. The final packing density of 800 nm particles reached 55-62%, depending on the surface charge of particles. On the other hand, the final packing density (41% density) of 30 nm SiC particles was not influenced by the surface charge, and was lower than that of 800 nm SiC particles. The consolidation energy for 1 cm3 SiC was 1.1-5.5 J/cm3 for 800 nm SiC particles and 17.2 J/cm3 for 30 nm SiC particles. Decrease of the pore size of the consolidated SiC compact increased the consolidation energy. The ratio of energy applied between two particles during consolidation to the interaction energy between two particles in a suspension was correlated to the packing density of the consolidated SiC cake.
