S.M. Dong et al. Ceramics International 28(2002)899-905 4. Conclusions [6 HH. Strecker, K P. Norton, J D. Katz, J.O. Freim, Microwave densification of electrophoretically infiltrated silicon carbide The composite without carbon coating and particu composite, J Mater. Sci. 32(1997)6429-6433 late loading demonstrates higher density and flexural [7 B.G. Ravi, V. Praveen, M. Panneer Sevam, K.J. Rao, Micro- strength. In this composite, a relative strong interface ave-assisted preparation and sintering of mullite and mullite. zirconia composites from metal organics, Mater. Res. Bull. 33 between matrix and fibers could be formed. The strong (1998)1527-1536 interface can provide the high ability for load transfer [8K. Jakubenas, H L. Marcus, Silicon carbide from laser pyrolysis from matrix to fibers and prevent the delamination of of polycarbosilane, J. Am. Ceram Soc. 78(1995)2263-2266 he fiber layers 9 S.T. Schwab, P F. Fleig T Chen, J D. Katz, T.w. Hardek, K w Buesking, Enhanced PIP processing of Sic/SiC for fusion appli The composites with carbon coating and particulate cations, in: Proceeding 3rd IEA International Workshop on Si loading present a relatively lower density and flexural Sic Ceramic Composites for Fusion Applications, 1998 strength. This composite has a relatively weak interface [] L.v. Interrante, C.W.Whitmarsh, w. Sherwood, H.Wu nd shows long fiber pull-out. During bending test shear fracture occurred leading to the delamination Res. Soc. Symp Proc. 346(1994)593-603 along the interlayers. With the adjustment of the filler [11 T. Hinoki, w. Yang, T. Nozawa, T. Shibayama, Y. Katoh addition in the impregnated polymer precursor and fiber A. Kohyama, Improvement of mechanical properties of SiC/sic coating, interfacial properties could be changed. This composites by various surface treatments of fibers, J. Nucl. implies that the fracture behaviors can be further mod Mater.289(2001)2329 ified to fit the requirement for preparing strong compo- [2]RJ. Kerans, R.S. Hay, N.J. Pagano, T.A. Parthasarathy, The role of the fiber-matrix interface in ceramic sites and or tough composites by PIMP process. Bul.68(1989)429442. [13 P D Jero, R.J. Kerans, T.A. Parthasarathy, Effect of interfacial roughness on the frictional stress measured using pushout tests, J Acknowledgements Am. Ceram.Soc.74(1991)2793-2801. [14 T.A. Parthasarathy, D B. Marshall, RJ. Kerans, This work was conducted at the Institute of the effect of interfacial roughness of fiber debonding and sti ing rittle matrix composites, Acta Metall. Mater. 42(1994)3773- Advanced Energy, Kyoto University, as a part of Core Research for Evolutional Science and Technology [15] F. Rebillat, J. Lamon, R. Naslain, E L. Curzio, M K Fe (CREST) program administered by Japan Science and T M. Besmann, Properties of multilayered interphases in SiC/SiC Technology Corporation JST) interfaces, J Am Ceram Soc. 81(1998)965-978. [16Y. Tanaka, Y Kagawa, Y.F. Liu, C Masuda, mechanism during high temperature fatigue References reinforced Ti alloy matrix composite, Mater. (2001)110-117 [K. Sato, A. Tezuka, O. Funayama, T. Isoda, Y. Terada, S. Kato, [17 S.M. Dong, G. Chollon, C. Labrugere, M. Lahaye, A. Guette, M. Iwata, Fabrication and pressure testing of a gas-turbine R. Naslain. D L Jiang, Characterization of some advanced Si based ceramic fibers, J. Mater. Sci. 36(2001) method, Comp. Sci. Tech 59(1999)853-8 [18 J.L. Bobet, J. Lamon, Thermal residual stress [2 G.D. Soraru, F. Babonneau, J.D. Mackenzie, Structural evolu- mposites-1 Axisymmetrical model and finite tions from polycarbosilane to SiC ceramics, J. Mater. Sci. 25 Acta Metall. Mater. 43(1995)2241-2253 (1990)3886-3893 [19 C.A. Hasegawa, A. Kohyama, R.J. Jones, L L. Snead, B] MJ. Wild, P. Buhler, On the phase composition of poly- B. Riccardi, P. Fenici, Critical issues and current status of Sic/ nethylsiloxane derived ceramics, J. Mater. Sci. 33(1998)5441 Sic composites for fusion, J Nucl. Mater. 283-287(2000)128- 544 4 G. Ziegler, I. Richter, D. Suttor, Fiber-reinforced composites [20 F. Rebillat, J. Lamon, A Guette, The concept of a strong inter- with polymer-derived matrix: processing, matrix formation and face applied to SiC/SiC composites with a BN interphase. Acta properties, Composites A30(1999)411-417. Mater.48(2000)4609-4618 5 M. Kotani, A. Kohyama, K. Okamuram, T. Inoue, Fabrication [21] F. Rebillat, J. Lamon, R. Naslain, E L. Curzio, M K. Ferber, f high performance SiC/SiC compos site b polymer Impregn T M. Besmann, Interfacial bond strength in SiC/SiC composite tion and pyrolysis method, Ceram. Eng. Sci. Proc. 20(1999)309- by single-fiber push-out tests, J Am Ceram. 316. Soc.8l(1998)2315-23264. Conclusions The composite without carbon coating and particu￾late loading demonstrates higher density and flexural strength. In this composite,a relative strong interface between matrix and fibers could be formed. The strong interface can provide the high ability for load transfer from matrix to fibers and prevent the delamination of the fiber layers. The composites with carbon coating and particulate loading present a relatively lower density and flexural strength. This composite has a relatively weak interface and shows long fiber pull-out. During bending test, shear fracture occurred leading to the delamination along the interlayers. With the adjustment of the filler addition in the impregnated polymer precursor and fiber coating,interfacial properties could be changed. This implies that the fracture behaviors can be further mod￾ified to fit the requirement for preparing strong compo￾sites and/or tough composites by PIMP process. Acknowledgements This work was conducted at the Institute of the Advanced Energy,Kyoto University,as a part of Core Research for Evolutional Science and Technology (CREST) program administered by Japan Science and Technology Corporation (JST). References [1] K. Sato,A. Tezuka,O. Funayama,T. Isoda,Y. Terada,S. Kato, M. Iwata,Fabrication and pressure testing of a gas-turbine component manufactured by a preceramic-polymer-impregnation method,Comp. Sci. Tech. 59 (1999) 853–859. [2] G.D. Soraru,F. Babonneau,J.D. Mackenzie,Structural evolu￾tions from polycarbosilane to SiC ceramics,J. Mater. Sci. 25 (1990) 3886–3893. [3] M.J. Wild,P. Buhler,On the phase composition of poly￾methylsiloxane derived ceramics,J. Mater. Sci. 33 (1998) 5441– 5444. [4] G. Ziegler,I. Richter,D. Suttor,Fiber-reinforced composites with polymer-derived matrix: processing,matrix formation and properties,Composites A30 (1999) 411–417. [5] M. Kotani,A. Kohyama,K. Okamuram,T. 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Guette,The concept of a strong inter￾face applied to SiC/SiC composites with a BN interphase,Acta Mater. 48 (2000) 4609–4618. [21] F. Rebillat,J. Lamon,R. Naslain,E.L. Curzio,M.K. Ferber, T.M. Besmann,Interfacial bond strength in SiC/SiC composite materials,as studied by single-fiber push-out tests,J. Am. Ceram. Soc. 81 (1998) 2315–2326. S.M. Dong et al. / Ceramics International 28 (2002) 899–905 905