摘要:
采用化学气相沉积工艺制备出炭毡增强炭/ 炭(C / C)复合材料和3 K 炭布叠层增强C / C 复合材料,并对材料进行 2500°C高温石墨化处理。利用X 射线衍射仪;偏光显微镜及拉曼光谱仪对所制材料进行表征。结果表明,炭毡C / C 复合材料基体是单一的高织构(HT)热解炭,3K 炭布叠层C / C 复合材料的基体是带状组织,从纤维表面向外依次为各向同性热解炭、HT 和中织构(MT)热解炭,其中HT 含量低于50% ;沉积态和热处理后,两种C / C 复合材料都具有相似的石墨化度,且热处理后的石墨化度超过80% ,但Lc 值差异明显,炭纤维、MT 和HT 热解炭的La 值均升高,其中HT 热解炭升幅明显大于炭纤维和MT 热解炭。HT 热解炭的含量是导致这两种C / C 复合材料具有相似石墨化度而Lc值却显著差异的原因。
Abstract:
C / C composites reinforced using carbon felt and 3 K carbon cloth laminated preforms were prepared by chemical vapor infiltration and samples taken from them were subsequently subjected to heat treatment at 2500°C. The microstructures of the C / C composites were characterized by X-ray diffraction, polarized light microscopy and Raman spectroscopy. Results showed that the matrix of composites reinforced with carbon felt contained only high textured (HT) pyrolytic carbon, while those reinforced with the 3 K carbon cloth had a banded texture composed of isotropic, HT and medium textured (MT) pyrolytic carbon when moving from fibers to matrix, and the content of HT pyrolytic carbon was less than 50% . Regardless of the preform, both the asprepared and heat treated composites had a similar degree of graphitization. The Lc value of the carbon felt reinforced composites was higher than their counterparts both for the asprepared and heat treated samples. The La values of the carbon fibers, MT and HT pyrolytic carbon increased after the heat treatment, and the La value of the HT pyrolytic carbon had a much larger increase than that of the others.
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