Microstructure characterization of CVI-densified carbon/carbon composites with various fiber distributions
Microstructure characterization of CVI-densified carbon/carbon composites with various fiber distributions
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DOI：
10.1016/j.compscitech.2012.08.009
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发表时间：
2012-10-12
影响因子：
9.1
通讯作者：
Piat, R.
中科院分区：
文献类型：
--
作者：
Dietrich, S.;Gebert, J. -M.;Piat, R.
多相复合材料的力学性能受微观组分的体积分数、取向分布和几何形状的影响。在通过化学气相渗透制造的碳-碳复合材料的情况下，微观成分是碳纤维、热解碳基质和孔隙。热解碳涂层的局部厚度变化、纤维分布和孔隙率是影响材料性能的主要因素。本文考虑了两种纤维排列方式：二维层合预制体和无规毡。材料的特征在于通过确定它们的密度和它们的纤维分布函数，通过建立存在于复合材料中的热解碳基质的类型，以及通过研究孔隙率。本文提出了一种利用X射线计算机断层摄影技术来估计任意形状的纤维和孔隙的取向分布的方法。提出了一种基于微结构图像处理的方法，随后对光纤周围的涂层生长进行数值模拟，以估计涂层的局部厚度。所获得的信息是适当的微观力学建模和预测的整体热机械性能的研究复合材料。(C)2012爱思唯尔有限公司保留所有权利。
Mechanical behavior of multi-phase composites is crucially influenced by volume fractions, orientation distributions and geometries of microconstituents. In the case of carbon-carbon composites manufactured by chemical vapor infiltration, the microconstituents are carbon fibers, pyrolytic carbon matrix, and pores. The local variable thickness of the pyrolytic carbon coating, distribution of the fibers and porosity are the main factors influencing the properties of these materials. Two types of fiber arrangements are considered in this paper: 2D laminated preform and random felt. The materials are characterized by determining their densities and their fiber distribution functions, by establishing types of pyrolytic carbon matrix present in the composites, and by studying the porosity. A technique utilizing X-ray computed tomography for estimation of the orientation distribution of the fibers and pores with arbitrary shapes is developed. A methodology based on the processing of microstructure images with subsequent numerical simulation of the coating growth around the fibers is proposed for estimation of the local thickness of the coating. The obtained information is appropriate for micromechanical modeling and prediction of the overall thermo-mechanical properties of the studied composites. (C) 2012 Elsevier Ltd. All rights reserved.