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Volume 17, Issue 4, 2008
LETTER: MICROSTRUCTURAL CHARACTERIZATION AND TENSILE BEHAVIOUR OF A 3D BRAIDED C/SiC COMPOSITE FABRICATED BY CHEMICAL VAPOUR INFILTRATION
Yiqiang Wang*, Litong Zhang, Laifei Cheng, Junqiang Ma
National Key Laboratory of Thermostructure Composite Materials, Northwestern Polytechnical University, 547 Mailbox,Xi’an Shaanxi 710072, People’s Republic of China
* Author to whom correspondence should be addressed, e-mail: wyq80@eyou.com
Received 21 April 2008; accepted 4 July 2008
ABSTRACT
The microstructure of a 3D C/SiC composite was characterized and the tensile behaviour was investigated in conjunction with acoustic emission (AE) technique. A computer model of the fibre architecture was generated for visualization and further stress analysis. The results show that the stress-strain curves exhibit mostly nonlinear behaviour with four distinguishable regions, which compare well with the AE characteristics. Microstructural observations reveal the superficial matrix cavities and large inter-bundle pores due to the 3D braiding fibre architecture. The failed specimens show ragged fracture surfaces and extensive fibre pullout, as well as interfacial debonding.
Keywords: Ceramic matrix composites; Fibre architecture; Microstructure; Tensile behaviour
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