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以T-300平纹炭布和聚丙烯睛(PAN)预氧化纤维网胎叠层针刺,经炭化后制备成准三维结构的圆筒复合织物,在化学气相沉积至一定密度后,用两种不同工艺制备了C/C复合材料。在金相显微镜下对材料的增强结构进行了分析,并对材料热物理性能进行了测定。结果表明,网胎纤维沿径向的针刺导入明显增强了材料的整体结构,导入的径向纤维以纤维簇的形式存在,并不完全与层间垂直,工艺过程对分布形式影响显著。800℃时,化学气相沉积(CVD)和树脂炭混合基体,中间经1 800℃高温处理的C/C复合材料其轴向和径向热扩散系数分别为0.064 cm2/s和0.026 7 cm2/s,比热容分别为1.928×103J/(kg.K)和2.278×103J/(kg.K);CVD和沥青炭混合基体,中间经2 500℃高温处理的C/C复合材料,其轴向和径向热扩散系数分别为0.159 cm2/s和0.067 cm2/s,比热容分别为1.597×103J/(kg.K)和1.713×103J/(kg.K)。对两种工艺造成热性能差异的原因进行了分析。
A T-300 plain carbon cloth and polypropylene (PAN) pre-oxidized fiber web were laminated and needle-punched. After carbonization, a three-dimensional cylindrical composite fabric was prepared. After chemical vapor deposition to a certain density, C / C composites were prepared by different processes. The microstructure of the material was analyzed under a metallographic microscope, and the thermophysical properties of the material were measured. The results showed that the radial needle punching of mesh fiber obviously enhanced the overall structure of the material. The radial fiber introduced was in the form of fiber clusters, which was not perpendicular to the layer. The influence of the process on the distribution was significant. At 800 ℃, the axial and radial thermal diffusivities of C / C composites were 0.064 cm2 / s and 0.026 7 cm2 / s, respectively, by chemical vapor deposition (CVD) and resin-carbon mixed matrix. , And the specific heat capacities were 1.928 × 103 J / (kg · K) and 2.278 × 103 J / (kg · K), respectively. The C / C composites with CVD and pitch-carbon mixed medium and high temperature treatment at 2 500 ℃ in the middle had an axial and radial The thermal diffusivities were 0.159 cm2 / s and 0.067 cm2 / s, respectively. The specific heat capacities were 1.597 × 103 J / (kg · K) and 1.713 × 103 J / (kg · K), respectively. The causes of the difference in thermal properties between the two processes were analyzed.