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| Effect of Interface on Mechanical Property and Oxidation Behavior of SiCf /SiC Composites |
| ZHANG Bingyu, WANG Ling, JIAO Jian, YANG Jinhua, LIU Shanhua |
| (AVIC Composite Corporation LTD, Beijing 101300, China) |
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Abstract In order to investigate the influence of interfaces on the mechanical properties and oxidation behaviors of
SiCf /SiC composites, SiCf /SiC composites with 3 different interfaces (PyC, PyC+BN-Ⅰ and PyC+BN-Ⅱ ) were prepared
via precursor infiltration and pyrolysis (PIP) method. Results showed that SiCf /SiC composites with PyC interface exhibited
the highest flexural strength of 380MPa. SiCf /SiC composites with PyC+BN-Ⅰ and PyC+BN-Ⅱ interfaces exhibited
flexural strengths of 282MPa and 259MPa, respectively. The flexural strength retention rate of SiCf /SiC composites with
PyC+BN-Ⅱ interface was 54% after heat treatment at 1200℃ in air for 2h, and all SiCf/SiC composites with different interfaces
exhibited brittle fracture after heat treatment. The microstructure of SiCf /SiC composites demonstrated that the oxidation
of interfaces and fibers caused the failure of the composites. Energy dispersive spectrometer had not detected oxygen
on SiC fibers of SiCf /SiC composites with PyC+BN-Ⅰ and PyC+BN-Ⅱ interfaces, which indicated that BN interface can
effectively protect fibers from oxidation.
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2017, 
