厚壁C/C复合材料分区CVI制备工艺研究

摘要

Using C3 H6 and FA resin as carbon resources,the integral carbon felt reinforced thick-wall C/C composites were prepared by combinational process of zoning control CVI and resin impregnation carbonization (PIC).The microstructure was observed by CT machine and PLM and thermodynamics properties are tested.In the mean time,the results was compared to thermal gradient CVI.The results indicate that microstructure is SL,pyrocarbon is distributed homogeneously in it.The efficiency of densification is increased by 50％,especially at the final densified stage,it show obvious goodness.Axial compressional strength are increased by 28.4％,while radial compression strength increased by 33.6％.The thermal properties kept unchanged.It can be concluded that zoning control CVI can improve efficiency of densification greatly and homogeneous distribution of pyrocarbon,lower cost and better thermal mechanical properties.%以整体毡为增强体,丙烯和糠酮树脂为前驱体,采用分区CVI法和树脂浸渍/固化、炭化相结合的工艺制备了厚壁C/C复合材料,用CT机和偏光显微镜观察了材料的微观结构,并进行了热力学性能测试,结果与热梯度CVI法进行了对比.研究结果表明:分区CVI法制备的热解碳为光滑层结构,整体密度均匀,与热梯度CVI工艺相比,总CVI增密效率提高了近一半,特别是沉积后期,表现出明显的优势.同时,轴向压缩强度提高了28.5％；径向压缩强度提高了33.6％.线胀系数相当.通过研究认为,分区CVI法能很好的提高材料的增密效率和增密均匀性,降低成本,且材料最终具有优异的热力学性能.