P.W.M. Peters et al. / Journal of the European Ceramic Society 20(2000)531-535 o the modulus of the laminate(E0/o=108.4 GPa at room temperature) is small, so that the matrix cannot contribute to a quasi-ductile stress-strain behaviour The intra-laminar shear strength(at room temperature 36 MPa)is rather high, which leads to limited fibre pull out visible at fracture surfaces of crossply specimens References I. Beyerle, D.s., Spearing Damage and failure in un ceramic matrIx composites. 2. Strife. J. R. Ceramic coat for carbon-carbon composites. eramic Bulletin. 1988.. 369-374 Fig.7.SEM-picture of fracture surface of 0o-ply in crossply specimen 3. Ohlhors, C.W.Vaughn, W.L. and Barratt, D.M., Current tested at room temperature research in oxidation-resistant carbon-carbon composites at NASA Langley, NASAReport N93-12456, 149-158, 1993 Tu. W. Lange, F. F. and Evans, A. G, Concept for damage. points of fibre/matrix contact are visible. These contact tolerant ceramic composite with "strong"interfaces. J. Am points realise fibre/matrix stress transfer quantified by Ceran.Soc.,1996,792).417-424 the intra-laminar shear strength indicated in Table 4. A 5. Marshall. D. B. Davis. J.B.. Morgan. P. E D. and Porter, J.R. possibility to increase quasi-ductile effects is to increase Interface materials for damage-tolerant oxide composites. Key the thickness of the fugitive interface, which however is Engineering materials. 1997. 127-131 27-36 6. Cain, M. G. Cain, R. L, Tye, A, Rian, P, Lewis, M. H and accompanied by a reduction of the intralaminar shear Gent, J. Structure and stability of synthetic interfaces in CMCs strength Key Engineering Materials, 1997. 127-131, 37-51 7. Knabe. H. Haug, T, Schafer. W. and Waldenmaier, T, Oxide Ceramic Matrix Composites for Aerospace Applications. Dornier Gmbh und dornier luftfahrt gmbh. friedrichshafen conclusions 8. Duran, A, Aparicio, M., Rebstock, K. and Vogel, w. D, Rein- filtration processes for polymer derived fibre reinforced ceramics. A Nextel 610 fibre reinforced mullite-based ceramic Key Engineering Materials. 1997. 127-131. 287-294 matrix on the basis of a fugitive interface has been 9. Clemens, F, private communication. characterised. The crossply laminate(0/90/0/90/0/90)s 10. Schneider. H. Okada. K. and Pask J. Mullite and Mullite with a room temperature strength of 177.4 GPa showed Ceramics, John Wiley Sons. New York 11. Peters, P. W. M., Martin, E. and Pluvinage, P, Influence of por. a moderate drop in strength up to 800oC and a stronger osity and fibre coating on engineering elastic moduli of fibre. decrease up to 1200oC. The contribution of the matrix reinforced ceramics(SiC/SiC) Composites, 1995, 26(2), 108-114.points of ®bre/matrix contact are visible. These contact points realise ®bre/matrix stress transfer quanti®ed by the intra-laminar shear strength indicated in Table 4. A possibility to increase quasi-ductile e€ects is to increase the thickness of the fugitive interface, which however is accompanied by a reduction of the intralaminar shear strength. 4. Conclusions A Nextel 610 ®bre reinforced mullite-based ceramic matrix on the basis of a fugitive interface has been characterised. The crossply laminate (0/90/0/90/0/90)s with a room temperature strength of 177.4 GPa showed a moderate drop in strength up to 800C and a stronger decrease up to 1200C. The contribution of the matrix to the modulus of the laminate (E0/90=108.4 GPa at room temperature) is small, so that the matrix cannot contribute to a quasi-ductile stress±strain behaviour. The intra-laminar shear strength (at room temperature 36 MPa) is rather high, which leads to limited ®bre pull out visible at fracture surfaces of crossply specimens. References 1. Beyerle, D. S., Spearing, S. M., Zok, F. W. and Evans, A. G., Damage and failure in unidirectional ceramic matrix composites. J. Am. Ceram. Soc, 1992, 75(10), 2719±2725. 2. Strife, J. R., Ceramic coatings for carbon±carbon composites. Ceramic Bulletin, 1988, 67, 369±374. 3. Ohlhors, C.W., Vaughn, W.L. and Barratt, D.M., Current research in oxidation-resistant carbon±carbon composites at NASA Langley, NASA-Report N93-12456, 149±158, 1993. 4. Tu, W., Lange, F. F. and Evans, A. G., Concept for damage￾tolerant ceramic composite with ``strong'' interfaces. J. Am. Ceram. Soc., 1996, 79(2), 417±424. 5. Marshall, D. B., Davis, J. B., Morgan, P. E. D. and Porter, J. R., Interface materials for damage-tolerant oxide composites. Key Engineering Materials, 1997, 127±131, 27±36. 6. Cain, M. G., Cain, R. L., Tye, A., Rian, P., Lewis, M. H. and Gent, J., Structure and stability of synthetic interfaces in CMCs. Key Engineering Materials, 1997, 127±131, 37±51. 7. Knabe, H., Haug, T , SchaÈfer, W. and Waldenmaier, T., Oxide Ceramic Matrix Composites for Aerospace Applications. Dornier GmbH und Dornier Luftfahrt GmbH, Friedrichshafen. 8. Duran, A., Aparicio, M., Rebstock, K. and Vogel, W. D., Rein- ®ltration processes for polymer derived ®bre reinforced ceramics. Key Engineering Materials, 1997, 127±131, 287±294. 9. Clemens, F., private communication. 10. Schneider, H., Okada, K., and Pask, J., Mullite and Mullite Ceramics, John Wiley & Sons, New York. 11. Peters, P. W. M., Martin, E. and Pluvinage, P., In¯uence of por￾osity and ®bre coating on engineering elastic moduli of ®bre￾reinforced ceramics (SiC/SiC). Composites, 1995, 26(2), 108±114. Fig. 7. SEM-picture of fracture surface of 0-ply in crossply specimen tested at room temperature. P.W.M. Peters et al. / Journal of the European Ceramic Society 20 (2000) 531±535 535