针刺炭纤维预制体结构单元对C/C复合材料性能的影响

采用6K炭纤维无纬布/网胎交替叠层及12K炭纤维无纬布/网胎交替叠层,在针刺工艺,致密化、热处理工艺完全相同的情况下,制备了密度为1.8g/cm3的热解炭/树脂炭双元基体的两种C/C复合材料产品,考察了针刺预制体结构单元对C/C复合材料性能的影响.结果表明,两种C/C复合材料的热学（垂直方向导热系数）、电学性能及石墨化度基本相当;而针刺6K炭纤维无纬布/网胎预制体C/C复合材料的拉伸、弯曲、压缩、层间剪切强度分别为127MPa,189MPa,263MPa,24.6MPa;其平行方向导热系数为54.6W/m＆#183;K,比常规针刺12K炭纤维无纬布/网胎预制体C/C复合材料相应提高了38％,32.2％,32.8％,38.9％,21％,彰显了细化针刺预制体结构单元对C/C复合材料力学性能的显著影响.

Effect of needled-carbon fiber preform structure units on properties of C/C composites

Two kinds of C/C composite material products of 1.8 g/cm3 with pyrolytic carbon/resin dual matrix were prepared by 6K carbon fiber non-woven cloth alternating layers and 12K carbon fiber non-woven cloth alternating layers, which were used by the same processes of needle punching, densification and heat treatment. The effect of needled preform structure units on properties of C/C composite was studied. The results show that the thermal property （thermal conductivity coefficient in the vertical direction）, electrical resistivity and graphitization degree between these two kinds C/C composites are equal basically. The strength of tensile, bending, compression and layers shear of C/C composite with needled 6K carbon fiber non-woven cloth preform is 127MPa, 189MPa, 263MPa, 24.6MPa and the thermal conductivity coefficient in the parallel direction is 54.6W/m＂ K, which increases by 38.0%, 32.2%, 32.8%, 38.9%, 21.0%, respectively, compared with the conventional C/C composite with needled 12K carbon fiber non-woven cloth preform. The paper revealed that the great effect on mechanical properties of C/C composite through refining needle preform structure units.