Design of a C/SiC functionally graded coating for the oxidation protection of C/C composites

To reduce the residual thermal stress between the carbon fiber-reinforced carbon (C/C) composites and the SiC coating layer, functionally graded materials (FGM) consisting of a C/SiC compositionally graded layer (C/SiC interlayer) were adopted. After designing the compositional distribution of the C/SiC interlayer which can relieve the thermal stress effectively, the deposition conditions of the entire compositional range of the C/SiC composites were determined using a thermodynamic calculation. According to the design and calculation the C/SiC interlayer and the SiC outer layer were deposited on the C/C composites by a low pressure chemical vapor deposition (LPCVD) method at deposition temperatures of 1100 and 1300 °C. The stress calculation and the experimental results suggested that the SiC-rich compositional profile in the FGM layer is the most effective for relieving the thermal stress and increasing the oxidation resistance.

[1]  J. C. Bressiani,et al.  Functionally gradient ceramic coating for carbon–carbon antioxidation protection , 2001 .

[2]  J. Sheehan,et al.  Ceramic coatings for carbon-carbon composites , 1988 .

[3]  D. Choi,et al.  Deposition of compositionally graded SiC/C layers on C–C composites by low pressure chemical vapor deposition , 2002 .

[4]  G. Camus,et al.  Kinetics and Mechanisms of Oxidation of 2D Woven C/SiC Composites: I, Experimental Approach , 1994 .

[5]  R. Naslain,et al.  Kinetics and Mechanisms of Oxidation of 2D Woven C/SiC Composites: II, Theoretical Approach , 1994 .

[6]  J. Y. Park,et al.  C/SiC Multilayer Coating for the Oxidation Resistance of C-C Composite by Low Pressure Chemical Vapor Deposition , 2003 .

[7]  Y. Inomata,et al.  Silicon Carbide Ceramics—1 , 1991 .

[8]  F. Maury,et al.  Chemical vapor co-deposition of C and SiC at moderate temperature for the synthesis of compositionally modulated SixC1-x ceramic layers , 1995 .

[9]  W. Kowbel,et al.  CVD and CVR Silicon-based functionally gradient coatings on CC composites , 1995 .

[10]  S. Awasthi,et al.  C/C Composite Materials for Aircraft Brakes , 1988 .

[11]  K. Auh,et al.  Effect of source gas composition on the synthesis of functionally gradient materials by CVD , 1996 .

[12]  K. Luthra.  Oxidation of carbon/carbon composites—a theoretical analysis , 1988 .

[13]  T. Hirai,et al.  Thermodynamics for the preparation of SiC-C nano-composites by chemical vapour deposition , 1990 .

[14]  J. Giddings,et al.  NEW METHOD FOR PREDICTION OF BINARY GAS-PHASE DIFFUSION COEFFICIENTS , 1966 .

[15]  Richard J. Day,et al.  Oxidation protection for carbon fibre composites , 1996, Journal of Materials Science.

[16]  G. Savage.  Carbon-carbon composites , 1993 .

[17]  T. Hirai,et al.  Thermal fatigue resistance of CVD SiC/C functionally gradient material , 1994 .

[18]  Y. Kogo,et al.  High-temperature oxidation behavior of SiC-coated carbon fiber-reinforced carbon matrix composites , 1999 .

[19]  N. Iwamoto,et al.  The improvement in oxidation resistance of CVD-SiC coated C/C composites by silicon infiltration pretreatment , 1998 .

[20]  E. Fitzer.  The future of carbon-carbon composites , 1987 .

[21]  T. Hirai,et al.  Thermal properties of chemical vapour-deposition SiC-C nanocomposites , 1991 .

[22]  M. Knudsen.  Die Gesetze der Molekularstrmung und der inneren Reibungsstrmung der Gase durch Rhren , 1909 .

[23]  T. Hirai,et al.  Preparation of Silicon Carbide Powders by Chemical Vapor Deposition , 1988 .

[24]  T. Hirai,et al.  Density and microstructure of CVD SiC-C nanocomposites , 1991 .

[25]  M. Ferraris,et al.  Protective glass coating for carbon-carbon composites , 1998 .

[26]  L. Vandenbulcke,et al.  The oxidation behaviour of two- and three-dimensional C/SiC thermostructural materials protected by chemical-vapour-deposition polylayers coatings , 1994, Journal of Materials Science.

[27]  J. Bokros.  STRUCTURE AND PROPERTIES OF PYROLYTIC CARBON. , 1970 .

[28]  N. Arai,et al.  Improvement of high-temperature endurance of C/C composites by double coating with SiC and glass materials , 1996 .

[29]  K. S. Ravichandran,et al.  Elastic Properties of Two‐Phase Composites , 1994 .

[30]  P. S. Turner.  Thermal-expansion stresses in reinforced plastics , 1946 .

[31]  Theodore M. Besmann,et al.  SOLGASMIX-PV, a computer program to calculate equilibrium relationships in complex chemical systems , 1977 .