Enhanced Mechanical Performance of SiCNWs@C/SiC Composites With a C Interphase via In Situ Polymerization‐Carbonization

ABSTRACT

SiC nanowires (SiCNWs)‐reinforced SiC composites are promising candidates for aerospace, transportation, and nuclear systems because of their low density, high strength, and oxidation resistance. However, the strengthening and toughening effects of SiCNWs‐reinforced SiC composites are limited by two factors: (i) strong interfacial bonding between the SiCNWs and the SiC matrix, and (ii) sintering aid‐induced erosion damage to the SiCNWs. Herein, a C interphase was introduced between the SiCNWs and the SiC matrix through a simple in situ polymerization‐carbonization process using resorcinol and formaldehyde, thereby producing SiCNWs@C/SiC composites. The composites, with a C interphase thickness of 120 nm and a SiCNWs content of 7 wt.%, exhibited an MSP strength of 901 MPa and a fracture toughness of 5.01 MPa·m ^1/2 , representing increases of 76.0% and 27.4%, respectively, compared with monolithic SiC. The enhanced mechanical performance was attributed to crack bridging and pull‐out of the SiCNWs, as well as to the C interphase, which promoted load transfer, crack deflection, and protection of the SiCNWs against erosion. This work provides a simple and effective interphase engineering strategy for improving the mechanical properties of SiC matrix composites and highlights their potential applications in aerospace, transportation, and nuclear systems.