Alumina ceramics prepared by pressure filtration of alumina powder dispersed in boehmite sol

The alumina ceramics was prepared by pressure filtration of electrostatically stabilized alumina and alumina-boehmite water suspensions and subsequent pressureless sintering of as-prepared compacts. The aggregates formation was avoided by stabilization of initial suspension through the regulation of interparticle forces. Nanoparticle boehmite sol was used as a dispersant for alumina suspension, it acts as a lubricant, and moreover it enhances the handling strength of the green compacts and also its sinterability. The kinetic analysis of sintering confirmed, that the definite boehmite addition (2.7 wt.% in green compact) affects positively the densification. The higher amount of boehmite addition has negative influence; it causes the flocculation of the suspensions and decreases the density of sintered bodies.