Deposition of compositionally graded SiC/C layers on C–C composites by low pressure chemical vapor deposition

To improve the oxidation and erosion resistance of the carbon-fiber reinforced carbon–carbon (C–C) composites, SiC/C compositionally graded layers were deposited between the C–C composite and SiC layer by the low pressure chemical vapor deposition method. The compositions of the graded layers were easily controlled in various steps by manipulating the input ratio of CH3SiCl3 to C2H2. The compositions of the SiC/C deposited layers were consistent with calculated compositions. All the SiC/C layers had dense microstructures and uniform distributions of C and SiC phases.