Particle connection in a two-component powder compact was quantitatively evaluated by electrical conductivity measurements. As a model system, an alumina powder (median size 0.33 μm, insulator) was mixed with an indium tin oxide powder (ITO, In2O3-SnO2, median size 0.20 μm, electronic conductor) in aqueous solutions at pH 3.0-10.3 to make different types of microstructures of the consolidated powder compacts. The rheological properties of the suspensions and the packing density and electrical conductivity of the powder compacts consolidated by filtration were greatly dominated by the dispersibility of the matrix phase particles (Al2O3) rather than by the dispersibility of the second phase particles (ITO). The Al2O3-ITO compacts prepared from a well-dispersed suspension at pH 3, showed a high electrical conductivity which was independent of the relative density (60-95%). Particle connection between ITO particles was formed in the consolidated green compacts. The electrical conductivity of the powder compacts processed with a high viscosity suspension at pH 10, was low and enhanced when the bulk density exceeded 60% relative density by sintering. The network of ITO particles was formed by a decrease in the distance between ITO particles during the densification.

Keywords: Particle connection, Two-component powder compact, Electrical conductivity, Alumina, Indium tin oxide