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探索了一种快速制备碳 /碳复合材料的新工艺——液相气化 CVI法。该工艺在沉积温度 80 0～ 14 0 0℃内 ,沉积时间 3h,多孔材料表观密度可达到 1.6 8g/ cm3,致密化速率达到 1.4～ 1.7mm/ h,致密化效率比报道的常规等温 CVI工艺要快 2个数量级以上。本文根据多孔介质传质传热学理论初步分析了该工艺快速致密的根本原因 ,采用偏光显微镜及扫描电镜观察了材料的微观组织结构及热解碳的生长特征 ,并测定了材料的表观密度及力学性能
A new rapid process for the preparation of carbon / carbon composites has been explored. The deposition time is 3h, the apparent density of porous material can reach 1.6 8g / cm3, the densification rate reaches 1.4 ~ 1.7mm / h, the densification efficiency is higher than the reported conventional isothermal CVI Process faster than 2 orders of magnitude. Based on the theory of mass and heat transfer in porous media, the fundamental reason of the rapid and compact process was analyzed. The microstructure and pyrolytic carbon growth characteristics were observed by polarized light microscope and scanning electron microscope. The apparent density And mechanical properties