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

Mechanical, thermal stability and ablation properties of nanosilica (SiO2) modified carbon fiber/phenolic composites have been investigated. NanoSiO2/carbon fiber/phenolic nanocomposites were prepared using chopped carbon fiber, phenolic resin and nanoSiO2 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% nanoSiO2 decreased by 23.55% and 61.11%, respectively. Microstructure investigations and X-ray diffraction studies reveal that nanoSiO2 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% nanoSiO2.