Microstructure and mechanical properties of 3D fine-woven punctured C/C composites with P_yC/SiC/TaC interphases  

作　　者：曾凡浩 熊翔 李国栋 黄伯云 罗健 

机构地区：[1]State Key Laboratory of Powder Metallurgy,Central South University [2]Powder Metallurgy Research Institute,Central South University

出　　处：《中国有色金属学会会刊：英文版》2009年第6期1428-1435,共8页Transactions of Nonferrous Metals Society of China

基　　金：Project(50872154)supported by the National Natural Science Foundation of China;Project(20080431029)supported by China Postdoctoral Science Foundation;Project supported by the Postdoctoral Science Foundation of Central South University,China

摘　　要：The 3D fine-woven punctured C/C-(PyC/SiC/TaC)composites,composed of PyC/SiC/TaC interphases and pyrocarbon (PyC)matrix,were synthesized by isothermal chemical vapor infiltration(ICVI)methods.The alternating layers and the structure of these composites were examined by polarized light microscopy(PLM),X-ray diffractometry(XRD)and scanning electron microscopy(SEM).It is found that the PyC matrix has rough laminar(RL)structure,the TaC layer has NaCl-type cubic structure,and the SiC layer has few wurtzite type 10H-SiC besidesβ-SiC structure.The effects of fiber coating and the bulk density on the tensile and flexural properties of composites along X or Y and Z direction were investigated.It is shown that fiber coated 3D woven punctured C/C composites have good tensile and flexural strength,and the maximum of flexural strength is 375 MPa in X or Y direction at density of 1.89 g/cm 3 ,which is about three times higher than that of samples without TaC/SiC fiber coating.The flexural strength and bending strength increase with increasing the density of the composites.The analysis of fracture surfaces reveals that fibers and fiber bundles are pulled out in composites,indicating that the composite exhibits a non-linear failure behavior through propagation and deflection of the cracks.The 3D fine-woven punctured C/C-（PyC/SiC/TaC） composites, composed of PyC/SiC/TaC interphases and pyrocarbon （PyC） matrix, were synthesized by isothermal chemical vapor infiltration （ICVI） methods. The alternating layers and the structure of these composites were examined by polarized light microscopy （PLM）, X-ray diffractometry （XRD） and scanning electron microscopy （SEM）. It is found that the PyC matrix has rough laminar （RL） structure, the TaC layer has NaCl-type cubic structure, and the SiC layer has few wurtzite type 10H-SiC besides β-SiC structure. The effects of fiber coating and the bulk density on the tensile and flexural properties of composites along X or Y and Z direction were investigated. It is shown that fiber coated 3D woven punctured C/C composites have good tensile and flexural strength, and the maximum of flexural strength is 375 MPa in X or Y direction at density of 1.89 g/cm^3, which is about three times higher than that of samples without TaC/SiC fiber coating. The flexural strength and bending strength increase with increasing the density of the composites. The analysis of fracture surfaces reveals that fibers and fiber bundles are pulled out in composites, indicating that the composite exhibits a non-linear failure behavior through propagation and deflection of the cracks.

关 键 词：复合材料结构 碳/碳化硅 三维微结构 热解碳 碳化钽 力学性能 无纺布 扫描电子显微镜 

分 类 号：TB332[一般工业技术—材料科学与工程] V214.8[航空宇航科学与技术—航空宇航推进理论与工程]