Fractal characterization of pore microstructure evolution in carbon/carbon composites  

作　　者：LI MiaoLing QI LeHua LI HeJun XU GuoZhong 

机构地区：[1]School of Mechatronic,Northwestern Polytechnical University,Xi’an 710072,China [2]Research Institute of Carbon-Carbon Composite,Key Laboratory of Thermostructure Composite Material,Northwestern Polytechnical University,Xi’an 710072,China

出　　处：《Science China(Technological Sciences)》2009年第4期871-877,共7页中国科学（技术科学英文版）

基　　金：Supported by the National Natural Science Foundation of China (Grant No. 50742008)

摘　　要：A fractal characterization approach was proposed to research pore microstructure evolution in car- bon/carbon (C/C) composites during the chemical vapor infiltration process. The data obtained from mercury porosimetry determinations were analyzed using the sponge fractal model and the thermo- dynamics relation fractal model, respectively. The fractal dimensions of C/C composites at different densification stages were evaluated. The pore microstructure evolution with densification time was studied by fractal dimension analysis. The results showed that C/C composites belong to porous frac- tal structure. The fractal dimensions increase on the whole with decreasing porosity as the densifica- tion proceeds. The fractal dimensions are influenced by the texture of pyrocarbon and decrease with increasing anisotropy from isotropic pyrocarbon to high textural one. Both the complicacy of pore structure and the textural morphology of pyrocarbon can be represented simultaneously by the fractal dimension. The pore evolution of C/C composites in the densification process can be monitored using fractal dimension.A fractal characterization approach was proposed to research pore microstructure evolution in carbon/carbon (C/C) composites during the chemical vapor infiltration process. The data obtained from mercury porosimetry determinations were analyzed using the sponge fractal model and the thermodynamics relation fractal model, respectively. The fractal dimensions of C/C composites at different densification stages were evaluated. The pore microstructure evolution with densification time was studied by fractal dimension analysis. The results showed that C/C composites belong to porous fractal structure. The fractal dimensions increase on the whole with decreasing porosity as the densification proceeds. The fractal dimensions are influenced by the texture of pyrocarbon and decrease with increasing anisotropy from isotropic pyrocarbon to high textural one. Both the complicacy of pore structure and the textural morphology of pyrocarbon can be represented simultaneously by the fractal dimension. The pore evolution of C/C composites in the densification process can be monitored using fractal dimension.

关 键 词：CARBON/CARBON composites PORE evolution porous medium FRACTAL mercury INTRUSION POROSIMETRY (MIP) 

分 类 号：TB332[一般工业技术—材料科学与工程]