Effect of nanosilica on the microstructure, thermal properties and bending strength of nanosilica modified carbon fiber/phenolic nanocomposite

Abstract Mechanical, thermal stability and ablation properties of nanosilica (SiO 2 ) modified carbon fiber/phenolic composites have been investigated. NanoSiO 2 /carbon fiber/phenolic nanocomposites were prepared using chopped carbon fiber, phenolic resin and nanoSiO 2 by compression molding. The ablation properties of composites were tested in an oxyacetylene torch. The results show that the linear and mass ablation rates of the composites after modifying with 5 wt% nanoSiO 2 decreased by 23.55% and 61.11%, respectively. Microstructure investigations and X-ray diffraction studies reveal that nanoSiO 2 reacts with char at high-temperature, forming ablation resistant silicon carbide. Mechanical analysis shows that the bending strength of the nanocomposite increases by about 13% after adding 3 wt% nanoSiO 2 .