Solid loading optimization of ceramic slurry to achieve high-performance silica-based ceramic core through vat photopolymerization

In the vat photopolymerization (VPP) 3D printing of ceramic cores, the solid loading is generally conducive to the microstructure and performance of products, owing to the improved bonding between adjacent layers and enhanced dimensional accuracy with increasing solid loading. In this work, the content of ceramic powder in photosensitive resin was optimized, the solid loading increased from 56 vol% to 68 vol%, and a novel curing model was established to explain the impact of solid loading on the printing precision. During sintering, the shrinkage is regulated to approximately 3 %, demonstrating a more homogeneous structure. The interlayer strength increased to 11.43 MPa while maintaining an apparent porosity of 23.47 %. Furthermore, the anisotropy of VPP-3D printed ceramic cores dependent on the solid loading was investigated. The ratio of vertical strength to horizontal strength (sigma V/sigma H) increased from 0.57 to 0.68 when the solid loading grew from 56 vol% to 68 vol%. At 1540 degrees C, the value of sigma V/sigma H was further enhanced to 0.81. This value met the precision casting criteria for ceramic cores effectively. This work can provide a reference for the investigation of high-solid-loading ceramic cores.