Influence of Compaction Pressure on the Properties of Silica Ceramic Cores

Based on the application background of the ceramic cores for the hollow blades, silica ceramic cores were prepared by dry-pressing and subsequent pressureless sintering. The silica powders coated by silicone resin were used as the raw materials. The influence of compaction pressure on the properties of silica ceramic cores was analyzed. The results showed that with the increasing of compaction pressure, both the shrinkage rate and apparent porosity of the samples decreased. On the contrary, the increasing compaction pressure promoted the increasing of bulk-density and bending strength of the samples. The phase composition of the sample was composed of amorphous and crystallized silica. A number of cracks formed at the crystallization front of the grain owing to the volume change of crystallized silica during the cooling.