Li et al. Ablation resistance of carbon fibre reinforced BN-SiaN, matrix (a) A a uncoated, linear ablation rate 0056 mm s, mass ablation rate 5 10gs; b Sic coated, linear ablation rate 0-044 mm s, mass ablation rate 2. 65 x 10gs 4 Ablation appearances of CFRN composites (a) (b) lum a in centre of ablated b on edge of ablated area 5 Scanning electron microscopy images of ablated surfaces of Sic coated CFRN composite with protection for the composite under the surface. Just References because of the resistance of SiC coating to the flame the strained and the ablation I.O. Paccaud and A Derre: Chem. Vapor. Depos, 2000,6(1), resistance of CFRN composite is improved 2. O. Paccaud and A. Derre: Chen. Vapor. Depas, 2000, 6, (1), Conclusions 3. Y.J. Lee and H. J. Joo: Composites A, 2004. 35A, 1285 4. D. P. Kim and J Economy: Chem. Mater, 1993. 5, 1216 A coating was prepared on the surface of CFRN 5. C G. Cofer, J Economy, YXu,A.Zangvil,ELCurzio,M.K composite by chemical vapour deposition using liqui Ferber and K. L More: Compos. Sci. TechnoL. 1996, 56, 967. anes as recursor and the effects of the coating 6. B. Li, C.R. Zhang F. Cao, S.Q. Wang, Y. B Cao and Y. G on the ablation behaviour of the composite were primarily Jiang: New Carbon Mater, to be published. investigated. The coating deposited was mainly amor- 7. B. Li, C.R. Zhang, F. Cao, S Q. Wang, Y. B. Cao and Y.G. ublished hous Sic and quite compact. The Sic coating played an 8.Y. J Lee and D J. Choi:J. Mater.Sci,2000,35,4519 important part in improving the ablation resistance of the 9. Y. Gogotsi, S. Welz, D. A. Ersoy and M. J. McNallan: Nature, 2001,411,(17),283 reduced obviously and the coated composite presented a 10. JnX, seo, s, x. Yoon, K Nhara and K H. Kim: Thin Solid Films lower linear ablation rate of 21 4% and a lower mass 11.k. Su E.E. remsen ablation rate of 51-6%. The presence of Sic coating ater,1993,5,547 prevented the flame from spreading to other regions and 12. w.v. Hough, C.R. Guibert and G. T. Hefferan: US Patent chemical erosion and the mechanical denudation of the 13. T Isoda, H. Kaya and H. Nishi: J Inorg. Organomet. Polym composite were restrained. As a result, the composite 14. B Li, C R. Zhang H F Hu and G.J. Qi: J. Finct Mater Device coated by SiC exhibited a much better ablation resi 2006,12,(5),447. 1134 Materials Science and Technology 2007 VOL 23 No 9with protection for the composite under the surface. Just because of the resistance of SiC coating to the flame, the spread of the heat is restrained and the ablation resistance of CFRN composite is improved. Conclusions A coating was prepared on the surface of CFRN composite by chemical vapour deposition using liquid carbosilanes as the precursor and the effects of the coating on the ablation behaviour of the composite were primarily investigated. The coating deposited was mainly amor￾phous SiC and quite compact. The SiC coating played an important part in improving the ablation resistance of the composite. The ablated area of the coated composite was reduced obviously and the coated composite presented a lower linear ablation rate of 21?4% and a lower mass ablation rate of 51?6%. The presence of SiC coating prevented the flame from spreading to other regions and from penetrating into the composite, and both the chemical erosion and the mechanical denudation of the composite were restrained. As a result, the composite coated by SiC exhibited a much better ablation resistance. References 1. O. Paccaud and A. Derre´: Chem. Vapor. Depos., 2000, 6, (1), 33. 2. O. Paccaud and A. Derre´: Chem. Vapor. Depos., 2000, 6, (1), 41. 3. Y. J. Lee and H. J. Joo: Composites A, 2004, 35A, 1285. 4. D. P. Kim and J. Economy: Chem. Mater., 1993, 5, 1216. 5. C. G. Cofer, J. Economy, Y. Xu, A. Zangvil, E. L. Curzio, M. K. Ferber and K. L. More: Compos. Sci. Technol., 1996, 56, 967. 6. B. Li, C. R. Zhang, F. Cao, S. Q. Wang, Y. B. Cao and Y. G. Jiang: New Carbon Mater., to be published. 7. B. Li, C. R. Zhang, F. Cao, S. Q. Wang, Y. B. Cao and Y. G. Jiang: Carbon, to be published. 8. Y. J. Lee and D. J. Choi: J. Mater. Sci., 2000, 35, 4519. 9. Y. Gogotsi, S. Welz, D. A. Ersoy and M. J. McNallan: Nature, 2001, 411, (17), 283. 10. J. Y. Seo, S. Y. Yoon, K. Niihara and K. H. Kim: Thin Solid Films, 2002, 406, 138. 11. K. Su, E. E. Remsen, G. A. Zank and L. G. Sneddon: Chem. Mater., 1993, 5, 547. 12. W. V. Hough, C. R. Guibert and G. T. Hefferan: US Patent 4150097, 1979. 13. T. Isoda, H. Kaya and H. Nishii: J. Inorg. Organomet. Polym., 1992, 2, 151. 14. B. Li, C. R. Zhang, H. F. Hu and G. J. Qi: J. Funct. Mater. Device, 2006, 12, (5), 447. a uncoated, linear ablation rate 0?056 mm s21 , mass ablation rate 5?4761023 g s21 ; b SiC coated, linear ablation rate 0?044 mm s21 , mass ablation rate 2?6561023 g s21 4 Ablation appearances of CFRN composites a in centre of ablated area; b on edge of ablated area 5 Scanning electron microscopy images of ablated surfaces of SiC coated CFRN composite Li et al. Ablation resistance of carbon fibre reinforced BN–Si3N4 matrix 1134 Materials Science and Technology 2007 VOL 23 NO 9