【摘要】 为使高性能碳／碳(C／C)复合材料在航天密封材料领域中得到进一步的应用,研究了碳布叠层以及碳毡结构的C／C复合材料在一定压力下气体的渗漏情况,对比试样为俄罗斯高强石墨密封环材料,采用扫描电镜观察分析气体通过C／C复合材料的途径。结果表明:C／C复合材料比高强石墨更适合用做航天动密封材料。碳毡C／C复合材料比碳布叠层C／C复合材料气密性更好。C／C复合材料中的穿刺纤维、贯穿基体的孔隙和裂纹以及纤维与碳基体的结合情况对密封材料的密封性能起到很大的影响。更多还原

【Abstract】 2D carbon/carbon composites with different densities lapped with 3K-carbon cloth were fabricated by two-step technique of thermal gradient CVI and HPIC(High-Pressure-Impregnation-Carbonization). Flexural properties, fracture morphology of carbon/carbon composites were tested by comparing with carbon felt sealing composites. The results show that the strength and modular of C/C composite made by mix techniques are greater than those of graphite sealing material; Carbon/Carbon composites with high density showed brittle fracture behavior and fracture surface was almost flat while low density composites were inclined to tough fracture, but the samples with tough fracture showed that a lot of carbon fibers were pulled-out. The graphite sealing material showed brittle fracture obviously. Polarized microstructure shows that the blending organization was formed in composites, which increase the interface area and extend the crack diffuse distance.更多还原