Effect of three-directional orthogonal preform weaving parameters on properties of C/C composites

Taking the three-directional orthogonal preform with different Z-direction fiber distance as the research object, the carbon/carbon (C/C) composites were prepared by the combination of chemical vapor infiltration and resin impregnation, and the effect of weaving parameters on the microstructure and bending performance of C/C composites were studied. The calculation model was established by taking the smallest repeated structure of three-directional orthogonal preform as a unit, and the relationship between fiber content and weaving parameters of three-directional preform was obtained and verified. The results show that the fiber content of preform is increased with the decrease of Z-direction fiber distance and X, Y-direction fiber layer distance; when the Z-direction fiber distance is increased, the twist deformation of the fiber interweave becomes larger, resulting in the change of the pore structure of the preform; under the same densification process, the change of pore structure affects the composition and distribution of carbon matrix in C/C composites, but has no effect on the morphology of carbon matrix; when the fiber content in X, Y-direction is increased and the distance between fibers in Z-direction is decreased, the flexural strength of the C/C composites is higher.