C/SiC Multilayer Coating for the Oxidation Resistance of C-C Composite by Low Pressure Chemical Vapor Deposition

Abstract

Functionally graded materials (FGM) consisting of C and SiC were deposited between the carbon fiber reinforced carbon (C-C) composites and the SiC coating layer by low pressure chemical vapor deposition (LPCVD) method to reduce the thermal stress. The compositions of the graded layers could be easily controlled to various steps by manipulating the input ratio of CH 3 SiCl 3 to C 2 H 2. The residual stresses for the designed compositional distribution were calculated by finite element method (FEM). The designed FGM layers were coated experimentally on the C-C composites and the oxidation behavior of the composites was investigated.