Effect of pyrocarbon content in C/C preforms on microstructure and mechanical properties of the C/C–SiC composites
Effect of pyrocarbon content in C/C preforms on microstructure and mechanical properties of the C/C–SiC composites
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DOI：
10.1016/j.msea.2008.11.026
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发表时间：
2009-02
期刊：
影响因子：
6.4
通讯作者：
Yong Zhang;Z. Xiao;Jiping Wang;Jianfeng Yang;Z. Jin
中科院分区：
文献类型：
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作者：
Yong Zhang;Z. Xiao;Jiping Wang;Jianfeng Yang;Z. Jin
采用化学气相渗透（CVI）法制备了4种碳纤维体积分数相同（32%）、热解碳含量不同（20%~ 50%）的准三维C/C预制体，采用液态硅渗透（LSI）工艺制备了C/C-SiC复合材料。研究了C/C-SiC复合材料的显微结构和力学性能。X射线衍射（XRD）分析结果表明，复合材料由β-SiC、C和Si三相组成。随着C/C预制体中热解碳含量的增加，C/C-SiC复合材料中形成的碳化硅含量减少，残余热解碳含量增加。通过力学性能测试，研究了基体和相组成对C/C-SiC复合材料力学性能的影响。结果表明，随着残余热解炭含量的增加，复合材料的弯曲强度和剪切强度逐渐增加。采用热解碳含量为42 vol.%的C/C预制体制备的C/C-SiC复合材料的弯曲强度和剪切强度分别为100 MPa和100 MPa达到了最高值。
Carbon fiber reinforced silicon carbide matrix (C/C–SiC) composites were prepared by liquid silicon infiltration (LSI) process, using four kinds of quasi-three-dimensional C/C preforms with the same fiber volume fraction (32%) but different pyrocarbon content (from ∼20% to ∼50%, in volume) filled by chemical vapor infiltration (CVI). The microstructure and mechanical properties of C/C–SiC composites have been investigated. X-ray diffractmeter (XRD) analysis results show the composites are composed of three phases of β-SiC, C and Si. With the increase of the pyrocarbon content in the C/C preforms, the content of formed silicon carbide in the C/C–SiC composites decreases but the residual pyrocarbon increases. Mechanical tests were performed to assess the role of the matrix and phase composition in the C/C–SiC composites. The results demonstrate that the flexural strength and shear strength of the composites increase gradually as the increase of the content of residual pyrocarbon. The flexural and shear strength of the C/C–SiC composite produced of the C/C preform with pyrocarbon content of ∼42vol.% reached the highest value.