石墨化温度对预氧丝针刺复合材料微观结构及力学性能影响

Effects of Heat Treatment Temperatures on the Microstructure and Mechanical Property of Needle-punched Composites Made by Oxidized Polyacrylonitrile Fibers

以国产预氧丝针刺毡作为预制体,先采用炭化、化学气相渗积工艺,再分别于不同温度下进行石墨化处理最终制备出预氧丝针刺复合材料,并对所制材料的微观结构及其力学性能进行表征。结果表明:预氧丝针刺复合材料的石墨化度随石墨化温度的提高而提高,最高达到54.19%,弯曲强度随之下降。试样基体为粗糙层热解碳结构,在2200℃热处理温度下的样品具有较好的光学活性,弯曲强度为102MPa,力学性能保持良好。

Theneedle-punched felts which were prepared by using oxidized polyacrylonitrile fibers （OPF）were used as performs. OPF needle-punched composites were finally prepared by carbonization process, chemical vapor infiltration and graphitization process at different temperatures. The microstructure and mechanical property of the prepared materials were characterized. The degree of graphitization is higher along with the improvement of heat treatment temperature and the highest graphitization degree is 54. 19%. However,the bending strength become low- er. The obtained C/C composites have rough layer pyrocarbon structure. The sample of heat treatment at 2200℃ has good optical activity and the bending strength of 102MPa. It keeps good performance.