Synergistic Enhancement Mechanism of Particle Gradation and Reactive Melt Infiltration on the Mechanical Properties of Sic Ceramics Via Vat Photopolymerization

Abstract

Vat photopolymerization (VPP) technology holds significant potential for fabricating high-precision SiC ceramic 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 ceramics is developed. The results shows that particle gradation slightly weakens the curing of SiC slurry but benefits the reactive infiltration process. The addition of fine particles (d50=3 μm) reduces residual silicon aggregation and promotes uniform β-SiC growth in silicon-rich regions during RMI process. As a result, the fracture mode of SiC transitions from purely intergranular fracture to a mixed mode of intergranular and transgranular fracture, significantly improving its mechanical properties. The final SiC ceramics achieve a bulk density of 2.996 g/cm3 and a maximum flexural strength of 401.33 MPa, which reflecting an approximate 86.32% improvement in strength. This method offers an effective solution for fabricating high-strength SiC ceramics with complex structures using VPP technology.

Keywords: Vat photopolymerization, SiC, Particle gradation, Reactive melt infiltration, mechanical properties