Preparation and Mechanical Properties of Continuous Carbon Nanotube Networks Modified C_f/SiC Composite

Abstract

Continuous carbon nanotube (CNT) networks were formed in Cf/SiC composites via freeze-drying method. Composites were fabricated by precursor infiltration and pyrolysis (PIP) process afterwards. The different distribution morphologies of CNTs in the preforms originating from the different CNT contents were analyzed while the influence of the distribution of CNTs was discussed in detail. Compared to composites without CNTs, the interfacial shear strength (ILSS) and the flexural strength of Cf/1%CNTs/SiC were increased by 31% and 27%, respectively, but the values of Cf/2.5%CNTs/SiC decreased as a result of lots of defects caused by excess CNTs. With the analysis of ILSS, the flexural strengths, and the fracture morphologies, CNTs effectively improved the weak interfacial strength between T700SC carbon fibers and SiC matrix.

Enhanced thermal conductivity and mechanical properties of 2D C f/SiC composites modified by in-situ grown carbon nanotubes

“…To date, several attempts have been made to introduce CNTs into the C f /SiC composites with the aim of enhancing their mechanical parameters and thermal conductivity. For example, Yu et al [28] embedded commercial multi-walled CNTs (0.0765 wt%) as raw materials in 3D preform via slurry infiltration, and then obtained C f /SiC composites via precursor infiltration and pyrolysis (PIP) technique. The results showed that the flexural strength and room-temperature thermal conductivity of the composites doped with CNTs were 311.4 MPa and 1.81 W•m −1 •K −1 , respectively, exceeding those of the pristine materials by 25% and 30%.…”

Joining of Cf/SiC Ceramic Matrix Composites: A Review

“…Carbon fiber-reinforced silicon carbide (C f /SiC) ceramic matrix composites, one of the most famous CMCs, are becoming the most promising candidates for hightemperature structural applications (as illustrated in Figure 1), such as sharp leading edges, nose cones, aeronautic jet engines, thermal protection systems for reusable atmosphere reentry vehicles [12,13], as well as optical components [14] and nuclear fusion/fission reactors [15,16], owing to their relatively low density (∼2 g/cm 3 ), high thermal conductivity (∼67 W/(m·K)), high strength (300-800 MPa) [17][18][19], low coefficient of thermal expansion (CTE, 3.0-3.1 × 10 −6 ·K −1 ), especially good stability and excellent oxidation and creep resistance at elevated temperatures [13,[21][22][23]25]. In particular, C f /SiC composites have shown significant improvements in fracture toughness and thermal shock resistance.…”