PIP法制备Cf/SiC复合材料过程中碳纤维的化学损伤

对先驱体聚碳硅烷浸渍裂解工艺(PIP)制备Cf/SiC复合材料过程中碳纤维损伤严重的问题, 系统地分析了在Cf/SiC复合材料制备过程中先驱体裂解对碳纤维的化学损伤. 研究结果表明, PIP工艺中碳纤维的化学损伤包括界面反应和基体向碳纤维内部的扩散反应. 其中聚碳硅烷(PCS)中的活性基团和碳纤维的化学反应并不严重, 而微量的氧气和杂质对碳纤维的化学损伤影响很大; 基体中硅等元素可向碳纤维内部扩散, 随着高温处理时间的延长而加深, 并形成脆性的界面层, 使碳纤维截面积减小. 在第一周期浸渍裂解过程中, 先驱体对碳纤维的化学损伤很少, 在后续周期中, 随着基体致密度的提高, 碳纤维的化学损伤有所增加. 

Chemical Damage of Carbon Fibers During Cf/SiC Preparation by PIP

The chemical damage of carbon fibers during the preparation of Cf/SiC composites by precursor infiltration pyrolysis(PIP)with polycarbosilane(PCS)was investigated systematically.The results show that the chemical damage includes interface reaction and interface diffuse,in which the active groups of PCS hardly react with carbon fibers.However,the oxygen and impurities can hurt carbon fibers largely.Silicon diffuses to carbon fibers more and more with the increasing of heat treatment time,and it is the main way of chemical damage of carbon fibers.The chemical damage of carbon fibers is slight in the first cycle,and turns heavier in the following cycles.