预氧丝网胎体积分数对针刺C/C复合材料力学性能的影响

Effect of Volume Fraction of Preoxidized Fiber Web on Mechanical Performance of C/C Composites Reinforced by Needle-Punched Fabric

以预氧丝网胎体积分数为35%、40%和45%针刺织物为坯体,经数次沥青浸渍/炭化、高温石墨化处理后制备C/C复合材料,测定并分析这三种材料的拉伸、压缩、弯曲和剪切强度;采用扫描电子显微镜对其断口形貌进行观察,研究预氧丝网胎体积分数对C/C复合材料力学性能的影响。结果表明:材料的z向力学性能(除了压缩强度)随着预氧丝网胎体积分数的增加呈单调递增关系,材料的xy向力学性能受预氧丝网胎体积分数影响较小。扫描电镜观察显示:材料z向强度主要与针刺形成的轴向纤维束多少、分布等有关。

Carbon/carbon composites were prepared by densifying through pregnation-carbonization and graphitization technology.The effect of volume fraction of pre-oxidized fiber web on the mechanical performance of carbon/carbon composites was studied by means of measuring the tensile strength,compression strength,flexural strength,shear strength,and fracture morphology of sample was observed by using scanning electron microscope.The results show that the mechanical performance in z direction（except compression strength） is increasing monotonously with increase of volume fraction of pre-oxidized fiber web,and the mechanical performance in xy-direction is little influenced by volume fraction of pre-oxidized fiber web.It is also found that the mechanical performance in z direction is closely related to the amount and distribution of the fiber in z direction.