Fibre-matrix interfacial zone in ceramic matrix composites: R. R.Naslain M M sic 3 500nm 100 (a) Figure 8(PyC-SiC)n multilayer interphases (TE ages), fabricated by: (a)conventional I-CVI(n=4; e(PyC)= 50 nm: e(SiC)=100 nm), and(b)P-CVI (n= 10; e(PyC)=20 nm: e(SiC)= 30 nm). according to Refs 46, 47 respectively the lifetime in oxidizing atmospheres of the materials, with REFERENCES respect to their counterparts with a simple PyC interphase has still to be transferred to real composite. cerphase but The concept has been extended to(BN-SiC 1. Aveston, J, Cooper, G. A and Kell re. In Proc. Conf on the properties m 2 F. w. and Mackin, T.J., The structural pc CONCLUSION rmance of ceramic matrix composites. In High Temperature Ceramic matrix composites are tough materials when the K. Jakus. Butterworth-Heinemann, Boston, 1995, pp 3-84 3. Naslain, R, Fiber-matrix interphases and interfaces in ceramic fibre-matrix bonding has been properly controlled during matrix composites processed by CVl. Composites Interface. rocessing, via the use of an interphase exhibiting a low enough failure shear strength. The interphase can be formed lain, R, The concept of layered interphases in SiC/SiC Ceram he fibre-matrix interfaces by in reactions or 5. Naslain, R.R., Interphases in ceramic matrix composites Ceram. deposited on the fibre surface prior to composite fabrication 1996,79,37 Four main types of interphase matrix composites, In High Temperature Ceramic Matrix Com promising in terms of design flexibility and mechanical osites, eds R. Naslain, J. Lamon and D. Doumeingts. Woodhead 7. Brennnan, J J. Interfacial chemistry and bonding in fiber reinforced structure materials or multilayers. Although it is relatively posites. Mater, Sci, Res, 1987. asy to fabricate non-brittle ceramic matrix composites achieving high mechanical properties and long lifetimes 8. Naslain, R and langlais, f, CVD composite materials. Mater. Sci. Research,, 1986, 20, 145. under load in oxidizing atmospheres at high temperatures Naslain, R. R. Ceramic matrix composites. Philosophical Trans requires a subtle design of the fibre-matrix interfacial zone. Encouraging results have been already obtained for glass- 10. Lowden, R. A, Fiber coatings and the mechanical properties of a ceramic and SiC-matrix composites with SiC based fibres, continuous fiber-reinforced SiC-matrix composite. In Designing Ceramic interfaces ll, ed S. Peteves CEC, Luxembourg, 1993 whereas the case of all-oxide composites remains an open field of research amAC5以m131 n, M. G. Devel ACKNOWLEDGEMENT history. In Designing Ceramic Interfaces I,ed, s, D. Peteves. CEC 14. DanieL. A. M. and Lewis. M. H. measurement of interfacial micro- The author is indebted to his colleagues from LCTS and x composites. British Ceram. Tr SEP for their contribution and valuable discussion, as well s J. Forget and M. Saux for their assistance in the 15. Lewis. M. H. Daniel. A. M. and Cain. M. G. Interface character- manuscript preparation Pmoc,l995,365,269 1153