基于液相热解沉积的C/C复合材料及其热物性研究

环己烷为前驱体,以体密度0.50g/cm3左右的T700(12k)炭纤维针刺毡为预制体,在自主设计的专用设备中用化学液相热解沉积工艺再结合热等静压工艺制备出1.75g/cm3C/C复合材料。借助偏光显微镜、扫描电镜对C/C复合材料的微观结构进行了研究,用耐驰NETZSCHLFA457MicroFlash激光热导仪对C/C复合材料热物性进行了分析,结果表明,该液相热解沉积工艺制备的C/C复合材料炭相多为粗糙层结构,沉积炭呈环形紧密包覆在炭纤维周围,炭纤维力学性能得以充分发挥。热物理性能测试结果表明,该复合工艺制备的C/C复合材料导热性能良好,热力学性能呈明显各向异性,线膨胀系数小,体积稳定性好。

Study on carbon/carbon composites and their thermophysical properties based on liquid phase pyrolysis deposition process

Using cyclohexane as precursor and T700(12k) fiber preform with bulk density of 0.50g/cm3 as preform, carbon/carbon composites with 1.75g/cm or more were prepared by chemical liquid phase pyrolysis deposition method combined with hot isostatic pressure densification processes in aself-designed special equipments. The microstructure of C/C composites was studied by means of polarizing microscope and scanning electron microscope. The thermal properties of C/C composites were analyzed by NETZSCH LFA 457 MicroFlash laser thermal conductivity meter. The results show that the carbon structure of carbon/carbon composites prepared by liquid phase pyrolysis processes is coarse layer structure.The mechanical properties of carbon fibers are fully developed. Thermophysical properties test results show that the C/C composite material prepared by the compound- process has good thermal conductivity, obvious anisotropy of thermomechanical properties, small linear expansion coefficient and excellent volume stability.