Microstructure and properties of liquid phase sintered SiC ceramics fabricated via selective laser printing and precursor impregnation and pyrolysis

Selective laser printing offers distinct advantages for fabricating large-scale and complex-shaped SiC ceramic components. However, the high porosity and low strength exhibited by SiC green bodies manufactured by selective laser printing necessitate an efficient heat treatment method to improve density and strength. This study presents an efficient technique for preparing SiC ceramics using selective laser printing coupled with precursor impregnation and pyrolysis (PIP) and liquid phase sintering (LPS). To enhance the density of the green body, a particle gradation technique was employed. Subsequently, a selective laser printing-powder, comprising SiC, Al2O3, Y2O3, and phenolic resin, was utilized to obtain a green body with a tailored microstructure. Following selective laser printing, SiC ceramics with flexural strength of 150 MPa and relative density of 98.2 % were produced by precursor impregnation and pyrolysis, followed by pressureless sintering. The outcomes of this study demonstrate a viable strategy for fabricating high-performance SiC ceramics via selective laser printing.