Gelcasting filling for small structure of hollow turbine blade ceramic mold

To improve the filling capacity of slurry and integrity of ceramic mold in process of fabricating the integral ceramic mold based on stereolithography, a negative pressure injection method is proposed, which focuses on small cooling holes of hollow turbine blade. The gel-casting filling process is investigated following the filling principle for a long and thin tube. A numerical simulation is carried out to reveal the effect of negative pressure injection on the mold filling capacity of slurry in small and complex structures, and the suitable pressure difference between the import and export is obtained. The negative pressure injection experiment and industrial CT detection are performed to verify the simulation results. The effect of negative pressure injection on the performance of ceramic mold is analyzed. It is found that the small cooling holes of hollow turbine blade can be duplicated without defects when the solid loading of alumina ceramic slurry possesses 60% and the pressure difference between the import and export reaches 0.03 MPa, and the density and strength of the green ceramic mold can be improved.