Carbon fiber/SiC composites modified SiC nanowires with improved strength and toughness

Abstract In this study, C f /SiC composite was modified with SiC nanowires (SiC nws ) grown in-situ in SiC matrix. Effects of SiC nw on bending strength and fracture toughness were investigated by comparison with conventional C f /SiC. Results showed that SiC nw significantly improved both strength and fracture toughness of C f /SiC. Compared to C f /SiC, flexural strengths of C f /SiC-SiC nw /PyC and C f /SiC-SiC nw composites increased from 363.1 MPa to 375 MPa and 466.9 MPa, respectively. Bending strength and fracture toughness were estimated to 565 MPa and 20.30 MPa m 1/2 for C f /SiC containing SiC nw at high temperature (1000 °C), respectively. These values were 13.2% and 16.1% higher than that of conventional C f /SiC. The latter was attributed to deflection, bridging, and pull-out of SiC nanowires to cracks. Improvements in mechanical properties of modified C/SiC composites were mainly attributed to deflection and bridging of SiC nanowires on cracks and pulling out of SiC nanowires from the matrix.