Preparation of carbon/silicon carbide composites based on selective laser sintering/reaction melt infiltration and its theoretical modeling calculations

In this study, porous carbon preforms with tailored pore structures were fabricated by selective laser sintering.Carbon/Silicon Carbide composites with improved overall performance were subsequently produced by infiltrating the porous preforms with liquid silicon, forming additional Silicon Carbide via in-situ reaction. Medium-carbon microspheres were introduced to control the porosity and enhance infiltration efficiency. The effects of natural flake-graphite addition on the mechanical properties, microstructure, and thermal conductivity of the composites were systematically investigated. When used as a slow-release carbon source, flake graphite delayed reaction-channel closure, promoting further Silicon Carbide formation and improving infiltration. Additionally, graphite acted as a thermally conductive filler, increasing the composite thermal conductivity. A maximum thermal conductivity of 75.86W/(m·K) was achieved with 50 wt% flake graphite. Incorporating 40 wt% flake graphite effectively mitigated the detrimental influence of residual free silicon, yielding the highest density (2.58 g cm −3 ) and flexural strength (173.4 MPa). By adjusting the carbon content and employing selective laser sintering, graphite-based preforms with controlled porosity and tailored properties were obtained, enabling the fabrication of high-performance Carbon/Silicon Carbide composites.Theoretical calculations and predictive modeling were performed in parallel; the models and equations were iteratively refined to establish a reliable property-prediction framework for the developed material system.