307 M K. Naskar et al. /Ceramics International 35(2009)3073-3079 Fig. 7. SEM fractographs of CZY sintered at (a) 1000C and(b) 1400C after the three-point bending tes Fig. 8. SEM fractographs of(a)CAZ and (b) CA sintered at 1000'C each after the three-point bending test. Fig 9. SEM fractographs of(a) CAS and(b)CA sintered at 1400C each after the three-point bending test. 4. Conclusions composites proved to be a key factor in optimizing the characteristics of the cmcs Sol-gel vacuum infiltration route was followed for the fabrication of near-net-shape CMCs using high alumina fibre Acknowledgements preform and various sols of single and bicomponent oxide systems as the infiltrates The sintering temperature affected the The authors thank Dr. H.S. Maiti, Director, Central crystallization behaviours of the matrix materials, fibre Glass Ceramic Research Institute(cG CRD, Kolkata preforms and composites as well. The flexural strength of for his constant encouragement and kind permission to the composites was dependent on their state of crystallization. publish this paper. They acknowledge the sincere helps Crystalline phases of the CMCs influenced the fibre-matrix rendered by the colleagues of X-ray Diffraction, SEM interface optimizing the fibre pull out and pseudo-ductility of ESCA and Composite Sections of cg Cri in materials the composites. Therefore, the crystallization behaviours of the characterization4. Conclusions Sol–gel vacuum infiltration route was followed for the fabrication of near-net-shape CMCs using high alumina fibre preform and various sols of single and bicomponent oxide systems as the infiltrates. The sintering temperature affected the crystallization behaviours of the matrix materials, fibre preforms and composites as well. The flexural strength of the composites was dependent on their state of crystallization. Crystalline phases of the CMCs influenced the fibre–matrix interface optimizing the fibre pull out and pseudo-ductility of the composites. Therefore, the crystallization behaviours of the composites proved to be a key factor in optimizing the characteristics of the CMCs. Acknowledgements The authors thank Dr. H.S. Maiti, Director, Central Glass & Ceramic Research Institute (CG & CRI), Kolkata for his constant encouragement and kind permission to publish this paper. They acknowledge the sincere helps rendered by the colleagues of X-ray Diffraction, SEM & ESCA and Composite Sections of CG & CRI in materials characterization. Fig. 7. SEM fractographs of CZY sintered at (a) 1000 8C and (b) 1400 8C after the three-point bending test. Fig. 8. SEM fractographs of (a) CAZ and (b) CA sintered at 1000 8C each after the three-point bending test. Fig. 9. SEM fractographs of (a) CAS and (b) CA sintered at 1400 8C each after the three-point bending test. 3078 M.K. Naskar et al. / Ceramics International 35 (2009) 3073–3079