C/C composites were prepared by adjusting the needling process with changing the needle diameter,needle density and preform density.In this paper,the effects of preform structure on the density and deposition rate of C/C com-posites were based on the same deposition process,as well as the effects of different needling processes on the flexural,ten-sile and thermal properties of C/C composites,were studied.The results showed that the C1 sample were prepared with felt-ing needle diameter of 0.7 mm,needle density of 26-31 needles/cm2 and preform density of 0.33-0.37 g/cm3,and it had average densification of 1.0 g/cm3 and average densification rate of 2.86 g/cm3·s after densification.As well as the overall mechanical properties of the C1 sample are the best,the interfacial strength of the specimen is moderate,and the phenomenon of fiber pull-out will occur when the load is applied,and the crack will be repeatedly deflected by the fiber inside the specimen,which exerts the toughening effect of the fiber.Compared with the C/C composites prepared by con-ventional process,the flexural strength is increased by 31%,the tensile strength is increased by 22.3%,and the maxi-mum compressive load is increased by 37%.
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