Effect of ratio of non-woven cloth to short-cut fiber web of the preform on the flexural properties of C/C composites

The effect of mass ratio of non-woven cloth to short-cut fiber web of needle-punched felt on the flexural properties of C/C composites was investigated. Results show that the flexural strength and modulus increase when the ratio of non-woven cloth to short-cut fiber web change from 7:3 to 6:4, and then decrease when the ratio of non-woven cloth to short-cut fiber web change from 6:4 through 5:5 to full short-cut fiber web. It can be explained on the base of hybrid fiber composites theory. There exists “hybrid synergetic effect” in the C/C composites with needle-punched felt as preform, which results in higher strength of C/C composites only when an optimal mass ratio of non-woven cloth to short-cut fiber web was adopted.