Enhancement of Dispersion and Fluidity of Aqueous Carbon Slurry by Addition of Various Dispersants

Abstract

It is well known that a carbon powder is one of the sintering aids of silicon carbide (SiC) to obtain the high fired density. Enhancement of the dispersion and fluidity of carbon slurry was a key subject in slip casting of aqueous SiC slurry, because of the hydrophobic surface and the high specific surface area of the carbon particles. The purpose of this study is to elucidate the optimum preparing conditions to obtain the dispersed, fluidized and thickened aqueous carbon slurry. Particle diameter of the carbon powder was 13 nm. As a dispersant, styrene/maleic copolymer (SM), poly-styrenesulfonic acid (HPSS) and naphthalene sulfonic acid formalin condensate ammonium salts (DEMOL-AS) were selected. Rheological behavior of aqueous carbon slurries with various dispersants was examined and evaluated. The dispersion and fluidity of aqueous carbon slurry was enhanced subsequently by the addition of DEMOL-AS.