（1.Science and Technology of Advance Functional Composite Laboratory, Aerospace Research Institute of Materials & Processing Technology, Beijing 100076, China) (2.Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China) (3.Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China）
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DOI:
10.7502/j.issn.1674-3962.2012.08.04
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Abstract:
The phase composition and microstructure features of a Cf/ZrC-ZrB2-SiC-C ultrahigh temperature ceramic matrix composite were characterized using Xray diffraction, scanning electron microscopy and transmission electron microscopy. A PyC layer of 2~3 μm in thickness, which was prepared by the CVI process, was observed as the interfacial layer between carbon fiber and the ultrahigh temperature ceramic matrix. The well crystallization combined the good thermal stability of this PyC layer protected the carbon fiber from damage during the cyclic PIP process to make the Cf/ZrC-ZrB2-SiC-C composites. Nanocrystalline ZrC particles of 20-30 nm in size were observed at the interface between carbon fiber and the PyC layer, ensuring the weak bonding between carbon fiber and the PyC layer. ZrC, ZrB2,SiC and graphite were identified in the matrix of theCf/ZrC-ZrB2-SiC-C composite. It was observed that the (002) plane of graphite was parallel to the surfaces of ZrB2 and SiC. No reaction layer or amorphous layer was detected at the interfaces between ZrB2 〖JP2〗and graphite, SiC and graphite, and ZrB2/SiC. An orientation relationship of ZrC (111) ∥Cg (002)，ZrC ［110］∥Cg［010］ was observed〖JP+1〗 between ZrC and graphite.