Investigation on pore characteristics of carbon fiber composite using micro-CT

Abstract

Carbon fiber reinforced resin matrix composite (CFRP) has been widely used in aerospace, military and other fields because of its low density and high strength. In composite components, the reliability of materials is significantly impacted by flaws like bubbles. The microscopic CT (computed tomography) technique is suitable for identifying material flaws. This paper takes CFRP as an example to study the pore structure characteristics. The porosity of the sample is 18.66%. Three distinct areas of the carbon fiber were chosen simultaneously, It makes up 98.58% of the pore size in the ROI (regions of interest)-1 area when the pore diameter is between 200μm and 400μm. When the pore size is 41.98-131μm, 98.58% of the total pore size is represented. The inner pore diameter of ROI-3 is 41.98-52.90μm, and there are 31,023 pores in total, which is 42.35% of all pores. The fractal dimensions of cuboid pore models in three distinct regions are centered in the ranges 1. 62-1.68, 1.52-1.55, and 1.35-1.38, respectively. This suggests that a significant portion of the pores at the microscale or even smaller scale are determined by the number of pores and that the filling capacity of pores varies, which is extremely important for the subsequent cross-scale seepage behavior and seepage law of composite materials.