Optimization of photosensitive resin formulation for additive manufacturing of high structural integrity SiC components

Vat photopolymerization 3D printing has been successfully used to produce silicon carbide ceramic with complex shape. However, the large polymerization shrinkage and intense pyrolysis behaviors of the photosensitive resin causes defects inside the ceramics. This paper proposes a photosensitive resin formulation with low shrinkage and high flexibility, which is composed of mono-functional monomers with a cyclic structure and an oligomer with a long aliphatic chain to form a three-dimensional cross-linked network. Meanwhile, this work introduces a non-reactive component to mitigate drastic thermal decomposition behavior. The photosensitive resin system has a low polymerization shrinkage and high reactivity, which is suitable for preparing ceramic slurries with high solid loading. Subsequently, the silicon carbide slurry with high solid content and high curing depth was prepared by mixing the silicon carbide powder and the optimal photosensitive resin. Finally, the silicon carbide parts with high structural integrity were achieved through 3D printing, low-stress debinding and liquid silicon infiltration process. The resin preparation strategies proposed in this article provides value references for the preparation of silicon carbide with high structural integrity by UV curing.