【摘要】 采用快速化学液相气化渗透法制备了碳/碳复合材料,沉积温度为850-1400℃,系统压力约0.1MPa.利用偏光显微镜及扫描电子显微镜观察了基体热解碳的微观组织结构及断口形貌特征;针对该技术特殊的致密化环境,研究了三种类型热解碳的形成条件及沉积过程;观察结果表明:粗糙层热解碳以层状方式生长,生长层面为曲面形状,热解碳微观结构呈现出锥形生长特征;同时测定了材料的力学性能,发现材料破坏形式属于剪切-拉伸的复式破坏,但拉伸破坏为主导形式,材料的纤维/基体粘结强度较高,薄弱环节是层间结合部位.更多还原

【Abstract】 C/C composites were fabricated by a rapid chemical liquid-vaporized infiltration (CLVI) processing. The deposition temperatures were in the range of 850- 1400℃, and the system pressure was about O.lMPa. The micro-morphologies and textural characteristics of pyrolytic carbon and fracture surfaces were observed by polarized light microscopy (PLM) and scanning electron microscopy (SEM). For the special densincation situations of CLVI, the forming conditions and densification course of three types of pyrocarbons were investigated preliminarily. At the same time, mechanical properties of the composite were examined, and the fracture characters and failure mode were also analyzed. The results show that rough laminar (RL) pyrocarbon grows with curved layers and the microstructure of RL pyrocarbon presents cone-like features. The materials damages with shear-tension form, while tensile destruction dominates the failure mode; the binding strength of fiber/matrix interface is higher, and the weak positions are located within interlayers.更多还原