J. Zhong et al. /Journal of Materials Processing Technology 190(2007)358-362 183sE ×1,seB1a Fig 3. The magnification of Zone C in Fig. 4 Fig. 6. The magnification of Zone B in Fig. 4 C B B A Fig 4. Fracture morphology of the C/C/SiC composite. Fig. 7. The magnification of Zone A in Fig. 4 thermal stress wound generate, which leaded to matrix cracking of composite. The micro-cracks could cause the deflection of 3.2. Analysis of phase structure and chemical composition the main crack when the material was subjected to load, which could improve the toughness of the composite. The XRD pattern showed in Fig 8 indicated that the matrix completely consisted of the amorphous substances, which was similar to the results in Refs. [8, 9]. Because the pyrolysis tem- which resulted in the non-crystalline structure of the matrix. The EDS pattern which was obtained from the position marked in Fig. 9 and the analysis result were given in Table 2, respectively It showed that the chemical compositions of matrix were mainly Si, C N and c seemed excessive according to the stoichiometric Elemental compositions of matrix of the as-prepared composite Element Atomic(%) 150 18.74 50.95 31.72 Totals 00.00 Fig. 5. The magnification of Zone B in Fig. 4360 J. Zhong et al. / Journal of Materials Processing Technology 190 (2007) 358–362 Fig. 3. The magnification of Zone C in Fig. 4. Fig. 4. Fracture morphology of the C/C/SiC composite. thermal stress wound generate, which leaded to matrix cracking of composite. The micro-cracks could cause the deflection of the main crack when the material was subjected to load, which could improve the toughness of the composite. Fig. 5. The magnification of Zone B in Fig. 4. Fig. 6. The magnification of Zone B in Fig. 4. Fig. 7. The magnification of Zone A in Fig. 4. 3.2. Analysis of phase structure and chemical composition The XRD pattern showed in Fig. 8 indicated that the matrix completely consisted of the amorphous substances, which was similar to the results in Refs. [8,9]. Because the pyrolysis tem￾perature was low and atoms did not have reactivity to crystallize, which resulted in the non-crystalline structure of the matrix. The EDS pattern which was obtained from the position marked in Fig. 9 and the analysis result were given in Table 2, respectively. It showed that the chemical compositions of matrix were mainly Si, C, N and C seemed excessive according to the stoichiometric Table 2 Elemental compositions of matrix of the as-prepared composite Element Weight (%) Atomic (%) C 34.03 49.54 N 15.02 18.74 Si 50.95 31.72 Totals 100.00 100.00