沥青过渡层对C／C复合材料力学性能的影响

Effect of transition layer using mesophase pitch on mechanical properties of carbon/carbon composites

在2D碳／碳(C／C)复合材料的碳纤维与基体热解碳间引入中间相沥青做过渡层,研究了中间相沥青的引入对C／C复合材料力学性能的影响．结果表明,与没有过渡层、普通沥青做过渡层、中间相沥青做过渡层的三类C／C复合材料比较,采用沥青做过渡层可以提高复合材料的力学性能,采用中间相沥青做过渡层制备的C／C复合材料的弯曲强度比采用普通沥青做过渡层提高44％,剪切强度提高15％．中间相沥青的引入可以使碳纤维束间和束内的结合强度不同,从而使基体断裂产生的裂纹扩散时发生偏转,复合材料的强度和韧性同时得到提高．

The mesophase pitch was used as transition layer between fiber and matrix of 2D carbon/carbon （C/C） composites. The effect of the transition layer on the mechanical properties of C/C composites was investigated by comparing with three kinds of manufactured C/C composites, that is, no transition layer, normal pitch as transition layer and mesophase pitch as transition layer. The results show that the mechanical properties are improved by using pitch transition layer, and the flexural strength and laminar interface shear strength （LISS） of C/C composites using mesophase pitch are improved by 44% and 15% respectively than that of C/C using normal pitch. The analysis of fractured surface shows that the bonding strength of intra-bundle and inter-bundle of fibers is different by using mesophase pitch, which cause crack to deflect during fracture. Therefore the strength and toughness are improved simultaneously.