Mechanical and oxidation protective properties of SiC nanowires-toughened SiC coating prepared in-situ by a CVD process on C/C composites

To improve oxidation resistance of SiC coating, a SiC nanowires-reinforced SiC (SiCNWs-SiC) coating was successfully prepared in-situ by a simple CVD process on carbon/carbon (C/C) composites. The coating could be divided into four layers with different density, but the whole is dense. The fracture toughness and oxidation protection effectiveness of the SiC coating were improved effectively by the nanowires. The test results showed that the fracture toughness of the SiC coating increased from 9.1 MPa m1/2 to 19.7 MPa m1/2 after introducing the SiC nanowires (SiCNWs), and the mass loss of the coated C/C composites was only 0.48% after oxidizing at 1637 K for 420 h, whereas the mass loss of pure SiC coated samples was up to 1.48% after oxidizing at 1637 K for 16 h.