High-strength Si-SiC lattices prepared by powder bed fusion, infiltration-pyrolysis, and reactive silicon infiltration

This study focuses on the design, additive manufacturing, and characterization of silicon carbide-based components with complex geometries. These parts were produced using a novel hybrid technique, previously developed: powder bed fusion of polyamide was used to 3D print two different templates with complex architectures. Preceramic polymer infiltrations and pyrolysis with polycarbosilane and furan resin were performed to obtain the ceramic parts. The final densification was achieved with reactive or nonreactive silicon infiltrations according to four different strategies, producing ceramics comprised of crystalline beta SiC, reaction-bonded beta SiC, and low residual silicon. The final gyroid samples (similar to 70 vol% macroporosity) exhibited a maximum compressive strength of 24.7 +/- 2.2 MPa, with a skeleton density of 3.173 +/- 0.022 g/cm3, and a relative density of 0.935 +/- 0.016. These findings underscore the potential of this manufacturing approach and showcase its effectiveness in fabricating intricate ceramic structures for engineering applications as heat exchangers and catalytic supports. Schematic representation of the process to produce dense SiC-SiC ceramics with complex architecture. image