Innovative ceramic paste for stereolithography additive manufacturing alumina core applied in turbine blade casting

Ceramic stereolithography 3D printing technology has demonstrated great potential in alumina core manufacturing for advanced turbine blade casting. However, there have been very few photosensitive material formulas specifically designed for alumina core fabrications. Herein, we present the design of a 3D printable ceramic paste based on bimodal particle size distributions for additive manufacturing of high-quality alumina cores. The coarse particles in the paste remain in their original shape while the fine particles transform into platelet-like particles during sintering. The effects of coarse particles, platelet-like particles, and grain growth on maintaining porosity and limiting shrinkage rates are studied. Furthermore, the vacuum sintering process is found to be beneficial for core material properties. The physical properties tests verify that the newly designed alumina paste in this work can meet the application requirement, which is superior to the previous research.