【摘要】 以碳毡为预制体,N2为稀释气体,甲烷为碳源前驱体,其分压为10kPa,滞留时间为0.15s的工艺条件下,研究了不同沉积温度对微波热解化学气相渗透(chemical vapor infiltration,CVI)工艺制备碳/碳复合材料的致密化速率、样品的体积密度及其密度均匀性的影响,并对其组织结构进行了观察。分析了沉积温度对微波热解CVI工艺制备碳/碳复合材料的密度与组织结构的变化规律。结果表明:在微波热解CVI工艺中,随着沉积温度的降低,碳毡预制体的致密化速率及最终体积密度呈现先升后降,1100℃沉积制备复合材料的密度均匀性最好,并呈现从内到外逐步沉积的规律。热解碳的织构主要为中等织构。更多还原

【Abstract】 The densification rate and the uniformity of bulk density of C/C composite samples prepared by microwave pyrolysis chemical vapor infiltration (CVI) were investigated with different deposition temperatures, using nitrogen gas as diluents, methane with a partial pressure of 10 kPa as carbon source gas, a residence time of 0.15 s. The textures of samples were also observed. The influence on the process of microwave pyrolysis CVI and textures of as-prepared samples were analyzed at different deposition tem-peratures. The results show that densification rate of the performs and the final bulk density of the samples increase first, and then fall with the decrease of deposition temperature. The density uniformity in the radial-direction of the samples is best at 1 100 ℃; the composites are densified from the inside out, and the textures of the matrix carbon are relatively uniform and are medium-textured.更多还原