Journal of Inorganic Materials

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Microstructures, Strength and Toughness of 2D Cf/(C-SiC) Composites by
Chemical Vapor Infiltration

MENG Zhi-Xin, CHENG Lai-Fei, ZHANG Li-Tong, XU Yong-Dong, HAN Xiu-Feng   

  1. (National Key Laboratory of Thermostructure Composite Materials, Northwestern Polytechnical University, Xi’an 710072, China)
  • Received:2008-12-15 Revised:2009-03-07 Online:2009-09-20 Published:2009-09-20
  • Contact: MENG Zhi-Xin

Abstract: Two dimensional carbon fiber-reinforced silicon carbide-carbon binary matrix composites (2D Cf/(SiC-C)) were fabricated by means of isothermal and isobaric chemical vapor infiltration (ICVI). The matrix structures of the 2D Cf/(SiC-C) composites were characterized by the backscattered electron imaging (BSE) of scanning electron microscope (SEM). Furthermore, their room temperature mechanical properties and fracture surfaces were compared with two dimensional carbon fiber-reinforced silicon carbide matrix composite (2D Cf/SiC). The results indicate that the matrices in the 2D Cf/(SiC-C) composites are multilayered structures composed of SiC and PyC layers. The PyC matrix layers are homogeneous and continuous, which are bonding well with SiC matrix layers. The 2D Cf/(SiC-C) composite with a thicker PyC matrix layer in fiber bundles exhibits better mechanical properties. Meanwhile, its tensile strength, failure strain, fracture toughness and fracture work are 3%, 142%, 22% and 58% higher than those of the 2D Cf/SiC composite, respectively. The multilayered matrices composed of SiC and PyC layers, cause the fibers in the 2D Cf/(C-SiC) composites to pull out twice in a concentrated mode. Moreover, the first pull-out fibers play a leading role in enhancing the strength and toughness.

Key words: binary matrix composites, microstructure, strength and toughness, chemical vapor infiltration

CLC Number: 

  • TB332