Boron nitride nanosheets composite SiC fibers with enhanced mechanical properties and high‐temperature resistance

Abstract Continuous SiC fibers with excellent mechanical properties and high‐temperature resistance possess immense potential as reinforcements for aeroengines. In this work, we prepared functionalized boron nitride nanosheet (F‐BNNS) composite SiC (F‐BNNS/SiC) fibers by polymer‐derived method. Due to the existence of F‐BNNS, the F‐BNNS/SiC fibers demonstrate an improved tensile strength up to 2300 MPa, representing a 25% increase compared to the original SiC fibers. Furthermore, owing to the chemical bonds established between the F‐BNNS and the SiC x O y network, the decomposition of the SiC x O y amorphous phase and the crystallization of SiC at high temperatures is effectively suppressed. The F‐BNNS/SiC fibers exhibit improved high‐temperature resistance, maintaining a tensile strength of 720 MPa up to 1500°C, while the SiC fibers completely degraded under the same conditions. The successful preparation of BNNS/SiC fibers may offer new insights into the performance enhancement of advanced ceramic fibers.