Effect of MnO ₂ –TiO ₂ and Nb ₂ O ₅ on the Fabrication and Properties of Alumina Ceramics Produced via Vat Photopolymerization

ABSTRACT Additive manufacturing of ceramics allows the production of complex, small‐batch parts. Among available methods, digital light processing (DLP) offers high‐resolution results with excellent surface finish. LCD‐based DLP printers are cost‐effective due to simpler optics, though they require suspensions with high solid content (> 40 vol%) and low viscosity (< 3 Pa·s). This study explores how MnO 2 –TiO 2 and Nb 2 O 5 sintering additives affect photosensitive slurries and the resulting Al 2 O 3 parts printed using an LCD system. Slurries were prepared with reactive alumina ( d 50 = 0.52 µm), PEGDA monomer, a phosphine oxide photoinitiator, and a phosphoric acid ester dispersant. At 50 vol% solids, they were analyzed for viscosity and curing behavior. Printed parts were evaluated for microstructure and mechanical properties. After sintering, MnO 2 –TiO 2 samples reached 95.9% relative density and 80.9 MPa flexural strength. Additives improved sintering kinetics, enhanced diffusion, promoted intergranular phase formation, and reduced delamination, highlighting their role in optimizing ceramic 3D printing.