Properties of alumina-based ceramic cores

Fused corundum is a rather promising raw material for preparing an alumina-based ceramic core due to its excellent high temperature resistance and chemical inertness. In this study, alumina-based ceramic cores were prepared using fused corundum as the matrix material, and the effect of varying silica powder contents on the properties of the alumina-based ceramic cores, including the sintering shrinkage, the flexural strength, and the high temperature deformation was investigated. The mineralization mechanisms of the silica on the alumina-based ceramic core were also analyzed. The optimum addition amount of silica in this experiment is 8% in weight. At that moment, the aluminum-based core has both a low sintering shrinkage coefficient of 0.66% and better properties: the room temperature flexural strength is 22.19 MPa, the high temperature flexural strength is 21.54 MPa, the high temperature deformation is 0.93 mm, and the residual flexural strength is 47.41 MPa.