Strengthening vat photopolymerization-fabricated SiC by particle gradation and reactive melt infiltration

Vat photopolymerization (VPP) technology holds significant potential for fabricating high-precision SiC components with complex structures. However, SiC, as a covalently bonded compound, exhibits low sintering activity, which greatly limits the densification process and its mechanical property. In this paper, a new bimodal particle size SiC combined with reactive melt infiltration (RMI) for fabricating high-performance SiC is developed. Compared with uniform particle sizes, a rational graded particle size distribution contributes to altering the single failure mode and enhancing the mechanical properties of SiC. During RMI, the incorporation of appropriate fine particles reduces the aggregation of residual silicon within SiC matrix, which confines the reaction between pyrolytic carbon and molten silicon to localized regions. This facilitates concentrated growth of the reinforcing β-SiC phase, serving as the key mechanism for performance improvement. The final SiC achieve a bulk density of 2.996 g/cm³ and a maximum flexural strength of 369.67 MPa, which reflecting an approximate 83 % improvement in strength. This method offers an effective solution for fabricating high-strength SiC with complex structures using VPP technology. © 2025 The Society of Manufacturing Engineers.