In-situ photothermal dual-curing of continuous SiC fiber-reinforced thermoset composite via additive manufacturing and post thermal treatment

Additive manufacturing (AM) of continuous fiber-reinforced composites enables the fabrication of lightweight and complex structures. However, only a few AM techniques can directly fabricate ceramic fiber–reinforced polymer composites, especially for continuous silicon carbide (SiC) fiber bundles, because SiC fiber bundles are brittle and break under the friction and tensile conditions of AM. Therefore, photothermally cured thermoset resins are proposed to be blended with SiC fiber bundles in in-situ impregnation and cured through a layer-by-layer manner. This study proposes a photothermal dual curing strategy integrating synchronized ultraviolet–infrared irradiation for the in-situ curing of SiC fiber–reinforced thermoset composites. The custom-built printing system used in this work can achieve stable fiber deposition and uniform cross-linking without molds or prepregs, as well as overcome poor impregnation and fiber–matrix interfacial defects. The process–structure–performance mapping of this novel process reveals a suitable strategy for balancing precision and efficiency. Post-curing reconstructs the cross-linked network, significantly enhancing stiffness and reducing energy dissipation. This work establishes a scalable route for the rapid fabrication of SiC composites with tunable fiber volume fraction ranging from 15% to 52%. This method provides a practical pathway for the fabrication of ceramic fiber–reinforced polymer composites and SiC ceramic green body with considerable potential advanced aerospace, thermal protection, and electromagnetic stealth applications.