Improving cure performance of Si3N4 suspension with a high refractive index resin for stereolithography-based additive manufacturing

Silicon nitride (Si₃N₄) slurries with high solid loading, low viscosity and good stability is difficulty prepared, due to low intrinsic surface charge and a large refractive index (RI) difference between Si₃N₄ powder and resin. In this paper, the curing behavior of Si₃N₄ slurry with different functional group and RI of resin monomer were systematically researched, and then the kind and optimum content of dispersant were investigated. Subsequently, a high solid loading Si₃N₄ slurry (44 vol%) with good curing behavior, low viscosity and favorable stability was successfully prepared. Lastly, the dense Si₃N₄ ceramic parts were fabricated by the suitable Si₃N₄ slurry (44 vol%) via stereolithography. After debinding and sintering process, the relative density and flexural strength of Si₃N₄ ceramic were 98.28% and 800 ± 27.28 Mpa, respectively.