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以4种纤维含量相同(32%,体积分数,下同),用化学气相渗透(chemical vapor infiltration,CVI)法制备了4种密度的碳纤维增强碳(carbon fiber reinforced carbon,C/C)多孔体,基体炭含量约20%～50%。利用液相渗硅法(liquid silicon infiltration,LSI)制备了C/C–SiC复合材料,研究了C/C多孔体对所制备的C/C–SiC复合材料微观结构和弯曲性能的影响。结果表明:不同密度的C/C多孔体反应渗硅后,复合材料的物相组成均为SiC,C及单质Si;随着C/C多孔体中基体炭含量的增加,C/C–SiC复合材料中SiC含量逐渐减少而热解炭含量逐渐增加。C/C–SiC复合材料弯曲强度随着材料中残留热解炭含量增加而逐渐增加,热解炭含量为约42%的C/C多孔体所制备的C/C–SiC复合材料的弯曲强度最大,达到320MPa。
Four kinds of carbon fiber reinforced carbon (C / C) porous bodies were prepared by chemical vapor infiltration (CVI) method with the same four kinds of fiber content (32%, volume fraction) , The base carbon content of about 20% to 50%. The C / C-SiC composites were prepared by liquid silicon infiltration (LSI) and the effects of C / C porous materials on the microstructure and bending properties of the prepared C / C-SiC composites were investigated. The results show that the phase composition of the composites is SiC, C and elemental Si when the C / C porous materials are reactively infiltrated by silicon. With the increase of carbon content in the C / C porous matrix, the C / C-SiC The content of SiC in the composites decreases and the content of pyrolytic carbon increases gradually. The flexural strength of C / C-SiC composites increased with the increase of residual pyrolytic carbon content in the composites. The bending strength of C / C-SiC composites prepared from porous C / C composites with a pyrolytic carbon content of about 42% The largest, up to 320MPa.