液相法制备炭/炭复合材料的显微结构

来源期刊：中南大学学报(自然科学版)2001年第5期

论文作者：熊翔 黄伯云

文章页码：494 - 497

关键词：炭/炭复合材料;液相法;焦炭填充料;显微结构

Key words：C/C composites; impregnation; coke fillers; microstructures

摘    要：采用光学显微镜和扫描电子显微镜对用液相法制备的3种单向纤维增强炭/炭复合材料的显微结构进行了观察和分析.这3种炭/炭复合材料分别采用纯沥青作基体和沥青加焦炭粉、树脂加焦炭粉作预浸初基体制得.在热压成形初坯体内,收缩的微裂纹沿纤维轴向与外界相通,可被再浸渍填充,而孔洞则大多与外界隔绝,不能被再浸渍填充.实验结果表明:焦炭填充料的添加改变了复合材料的显微结构,可调整炭/炭复合材料的纤维体积分数,减少气孔的形成,有利于再浸渍致密化;它还扰乱基体层状结构组织,导致其围绕焦炭粉颗粒呈紊乱状态.

Abstract: Three kinds of unidirectional fibre-reinforced C/C compositeswere fabricated bythe liquidmethod using pitch,pitch plus coke and resin plus coke during the prepregnation. Theirmicrostructureswere studiedwith optical metallography and SEM. In primary green composites, shrinkage cracks are formedmostly alongthe fibre axial and connected to the outside. They can be easily reimpregnated. However, pores are usually isolated from the outside and can not be reimpregnated. The coke fillers can modify the microstructures and give rise to improved homogeneity of the composite structures. The use of filler particles could facilitate the control of fibre volume fraction and reduce the pores formed duringmoulding. So, the samples with coke fillers can be reimpregnated to get higher densities. On the other hand, coke particles interfere with the layer microstructure of the carbon base.