Effects of Organic Dispersants on the Dispersion, Packing, and Sintering of Alumina

Abstract

The effects of water‐soluble polymers and benzoic acid derivatives on green and sintered Al 2 0 3 compacts were studied for two types of alumina powder. The percent of theoretical density achieved by each Al 2 0 3 sediment was dependent primarily on the concentration of water‐soluble polymeric dispersant rather than on the pH. Aromatic acids, such as 4‐hydroxy‐ and 4‐aminobenzoic acid, were also effective dispersants. The final density and grain size of sintered compacts depended on the green microstructure of the compacts and on differences in the concentration of trace elements in the two powders.