原位生长碳纳米管增强SiCf/SiC复合材料的力学性能

SiC fiber reinforced SiC matrix composites (SiCf/SiC) have been considered as promising high-temperature structural material for a variety of advanced applications in aeronautic & aerospace and fusion systems. The key route to improving the mechanical properties of SiCf/SiC composites lies in tailoring the interphase bonding between the fiber and the matix. In this study, carbon nanotubes (CNTs) were in situ grown on SiC fiber by chemical vapor deposition (CVD) process to ameliorate the interfacial bonding between fiber and matrix, as well as secondly reinforcing SiCf/SiC composites. The results show that the mechanical properties of SiCf/SiC composites were elevated as a result of the introduction of in–situ grown CNTs. Fracture toughness was enhanced by 106.3% when the volume fraction of CNTs reached 5.31%. The bonding between fiber and matrix became weakened by the in-situ grown CNTs, which made a great contribution to the pullout of fiber and resulted in the improvement of fracture toughness. In addition, the pullout of CNTs is also believed to be beneficial to the fracture toughness.