变密度针刺碳纤维预制体及其力学性能

Variable density needled carbon fibre preform and its mechanical properties

设计了一种表层密度较低而里层密度较高的变密度无纬布/网胎层针刺炭纤维预制体。对制得的变密度预制体和恒密度预制体,通过用排水法测试比较预制体的实际密度和孔隙率,用扫描电子显微镜(SEM)分析变密度预制体预制体的切面结构,用毛管流动孔隙仪分析比较预制体孔径分布,通过万能力学强力仪测试比较预制体弯曲力学性能,并对其在CVI制备C/C复合材料过程中的优点进行了展望。

The kind of variable density needled carbon fibre preform which density of surface layer was lower than middle layer was designed.For the prepared preform and constant density preform,using a water method tests to compare the actual density and porosity of preform.Scanning electron microscope（SEM）was used to analysis section structure of the preform,using capillary flow to analyze and compare the pore size distribution of the preform.And mechanical strength tests were conducted to compare bending mechanical properties of the preform.Its advantages in the preparation of C/C composite materials were discussed.