高密度轴棒法C/C复合材料的热膨胀性能  

Thermal expansion property of high-density C/C composites woven with axial carbon rods

作　　者：高亚奇[1] 邓红兵[2] 邹武[1] 程文[1] 吴书锋[1] 

机构地区：[1]西安航天复合材料研究所,西安710025 [2]航天动力技术研究院,西安710025

出　　处：《固体火箭技术》2010年第3期332-335,344,共5页Journal of Solid Rocket Technology

基　　金：973项目(2006CB600902)

摘　　要：以轴棒法4D编织预制体、高温煤沥青为前驱体,采用常压、高压相结合的液相浸渍-炭化技术制备高密度(≥1.95 g/cm3)的C/C复合材料,并研究了轴棒法编织C/C复合材料在RT^1000℃的热膨胀性能及其影响因素。结果表明,由于材料预制体编织结构与微观结构的界面裂纹具有方向性,导致了C/C复合材料热膨胀表现出明显的各向异性,径向热膨胀系数低于轴向,高温尺寸稳定性较好;轴棒法C/C材料的热膨胀行为在800℃出现拐点,拐点与材料界面裂纹愈合有关,受最终制备温度的影响很大;材料经2500℃热处理之后,拐点后延,整体热膨胀系数下降,随温度上升趋势变缓。By taking 4D preform woven with axial carbon rods as reinforcement phase and high temperature coal-tar pitch as matrix precursor,the C/C composites were prepared by using combined normal and high pressure impregnation-carbonization technique.Thermal expansion property of the C/C composites from RT to 1 000 ℃ was studied and the influencing factors on the thermal expansion property were discussed.The results show that the obvious anisotropy in coefficient of thermal expansion（CTE）of C/C composites presents due to both the preform structure and the directivity of the microstructure interfacial cracks.CTE along radial direction is lower than that of axial direction,and high temperature dimension stability is better.An inflexion point for expansion behavior of C/C composites occurs at 8 00 ℃,which is relative to the union of interfacial cracks.The corresponding temperature of the inflexion point is greatly influenced by the final preparation temperature.After high temperature treatment at 2 500 ℃,the inflexion point shifts toward higher temperature and the CTE declines,with temperature rising,tendency mitigates.

关 键 词：高密度 C/C复合材料 轴棒法 热膨胀系数 

分 类 号：TB33[一般工业技术—材料科学与工程]