Enhanced molding and mechanical properties of SiC-based ceramic lattice structures via digital light processing

Silicon carbide (SiC) ceramic lattice structures (CLSs) hold significant potential for use in structural components and optical mirrors in space exploration due to their light weight, high strength, and excellent dimensional stability. However, they face challenges such as poor curing performance and weak mechanical strength during the digital light processing (DLP) additive manufacturing process. In this study, SiC@Al2O3 powder was prepared, resulting in a 21 % reduction in absorptivity compared to bare SiC powder. The ceramic paste derived from this powder achieved a curing thickness of up to 80 mu m, exhibited a reduced over-curing width, and demonstrated a 75 % improvement in stability compared to bare SiC paste. Consequently, high-quality triply periodic minimal surfaces (TMPS) structured SiC@Al2O3 CLSs green bodies were successfully fabricated. By integrating precursor impregnation pyrolysis with the reaction melting infiltration (PIP-RMI) post-treatment densification method, SiC@Al2O3/Si CLSs were produced, exhibiting superior mechanical properties with low dimensional shrinkage. At 30 % volume fraction, the specific compressive strength of the primitive-TPMS SiC@Al2O3/Si CLSs reached 24.79 MPa. This study presents an effective method for fabricating SiC-based CLSs and establishes a foundation for the optimization of SiC ceramic fabrication processes.