Effects of SiC nanowire decorated with carbon nanosheet on mechanical, heat-dissipation and anti-ablation properties of carbon/carbon composites

摘要

Carbon/carbon (C/C) composites containing SiC nanowires (SiC NW) decorated with carbon nanosheet were prepared with the pyrolytic carbon (PyC) as the matrix, where the nanowires and carbon nanosheet were introduced via electrophoretic deposition and chemical vapor deposition respectively. Their flexural strength, heat-dissipation capacity, and anti-ablation properties were investigated, with C/C composites and carbon nanosheet-C/C composites as comparison. Flexural strength of the SiC NW-Carbon nanosheet-C/C(SiC NW-CN-C/C) composites increased by 40.97% and 65.69% separately due to improvement of the interfacial bonding and bonding between PyC sublayers via SiC NW and carbon nanosheet. Their heat-dissipation performance behaved better due to in-situ grown carbon nanosheet, with lower surface temperature when heated under the same condition. Consequently, the anti-ablation property of such composites was promoted with mass ablation rate decreased by 40.74% and 27.27% respectively, which was attributed to the enhanced bonding, the reduced thermal damage benefitted from better thermal performance, and the formation of SiC NW-Carbon nanosheet-PyC (SiC NW-CN-PyC) micro-rods to prevent debonding under impact of the high-speed gas flow and protect carbon fibers against mechanical ablation.