Ceramic matrix composites toughening mechanisms

Rice RW, Ceramic matrix composite toughening mechanisms. An update. Ceramic Eng Sci Proc, 5(7-8), 589-607, 1985. 

Reprint from Acta Materialia, Vol. 52, Xia Z., Ricster L., Curtin W.A., LiH., Sheldon B.W., Liang J., Chang B. and Xu J.M., Direct observation of toughening mechanisms in carbon nanotube ceramic matrix composites, pages 931-944, Copyright (2004) with permission from Elsevier. 

The toughening mechanism of fibre-reinforced ceramic-matrix composites is due to the pull-out phenomenon of the fibre from the matrix. For 3-D C/SiC composites three kinds of pull-out are observed from the fracture, namely the fibre pull-out, the fibre cluster pull-out and the bundle pull-out illustrated in Figure 5.12a, b and c respectively. 

In Table 18.6 we list different toughening mechanisms for ceramic-matrix composites (CMCs). Illustrate each mechanism using a sketch and, where appropriate, indicate the differences between using particles, platelets,... 

The combination of tiiese factors affects a number of strengthening and toughening mechanisms which can be exploited in glass and glass-ceramic matrix composite materials. 

Mechanisms of toughening in ceramic matrix composites are discussed by Rice [236,237] and Marshall [238] deals with failure mechanisms in ceramic matrix composites. 

Yamada K, Matsubara M, Suzuki N, Fukuda S, Matsumoto M, High temperature toughening mechanisms of particle and particle-fibre reinforced SiC composites, Evans AG, Naslain R eds., American Ceramic Soc, Inc, High-Temperature Ceramic-Matrix Composites I, Design, Durability and Performance, Proc 2nd Int Conf, Ceramic Trans, Santa Barbara, 57, 413-418, Aug 21-24 1995. 

Fig. 8.37 Schematic illustration of the primary toughening mechanisms in ceramics and ceramic-matrix composites. Note that all mechanisms are extrinsic in nature and promote inelastic deformation which results in a nonlinear stress/strain relationship [4]. With kind permission of Professor Ritchie...

Rice, R.W, Mechanisms of toughening in ceramic matrix composites. Ceram. Eng. Sci. Prop. 1981, N2, 65I-70I. 

MIY95] MIYAJIMA T., YAMAUCHI Y. and OHJI T., High temperature R-curve behavior and failure mechanisms of in-situ toughened composites , Lfzg/z Temperature Ceramic-Matrix Composites I Design, Durability and Performance, Ceramic Trans., Ed. Evans A.G. and Naslain R., vol. 57, p. 425-430, Amer. Ceram. Soc., Ohio, 1995. 

---