Effect of silica sol on the properties of alumina-based ceramic core composites

Abstract

A series of alumina-based ceramic cores sintered at 1300 °C, 1400 °C, and 1500 °C for 5 h were prepared, and the phases and microstructures were characterized by X-ray diffraction and scanning electron microscopy. The effect of colloidal silica sols on the properties of ceramic core was discussed. The properties of these materials were determined. The microstructure of the core formed on the substantially un-reacted coarse Al 2O 3 particles was predominantly a polycrystalline composition consisting essentially of in situ synthesized 3Al 2O 3·2SiO 2. The colloidal silica sol contents do not have an appreciable effect on the densification and shrinkage of alumina ceramic core. The ceramic cores of 5 wt% colloidal silica sol contents sintered at 1500 °C for 5 h showed the smallest creep deformation in the present research.