硼酸浸渍碳纤维对激光石墨化效果的影响

Influence of boric acid impregnation of carbon fiber on laser graphitization effect

在激光石墨化前对聚丙烯腈(PAN)基碳纤维进行硼酸(H_(3)BO_(3))浸渍处理,通过改变H_(3)BO_(3)含量和H_(3)BO_(3)浸渍时间考察H_(3)BO_(3)浸渍对激光石墨化效果的影响,采用拉曼光谱仪和X射线衍射仪对石墨化碳纤维的化学结构和微观形貌进行表征。结果表明:微量的硼可以进入石墨片层结构,石墨碳微晶的堆叠厚度L_(c)增大、石墨片层间距d_(002)减小、方位角半高宽减小、结晶度提高,同时石墨化程度提高;而过量的硼使得微晶结晶度和石墨化程度降低;在H_(3)BO_(3)含量和浸渍时间相同条件下,随着激光功率的增加,碳纤维石墨化程度显著提高。

Polyacrylonitrile(PAN)-based carbon fibers were impregnated with boric acid(H_(3)BO_(3))before laser graphitization.The influence of H_(3)BO_(3) impregnation on laser graphitization effect was investigated by changing H_(3)BO_(3) content and impregnation time.The chemical structure and microscopic morphology of the graphitized carbon fibers were characterized by Raman spectrometer and X-ray diffractometer.The results showed that trace boron could enter the graphite lamellar structure,the stacking thickness L_(c) of graphite carbon microcrystals increased,the graphite lamellar spacing d_(002) decreased,the azimuth half-height width decreased,the crystallinity increased,and the degree of graphitization increased.However,excessive boron decreased the microcrystal crystallinity and graphitization degree.Under the same H_(3)BO_(3) concentration and impregnation time,the degree of graphitization of carbon fibers increased significantly with the increase of laser power.