第2期
第19卷 2011年2月
文章编号
1004-924X(2011)02-0482-05
光学精密工程
Optics and Precision Engineering
Vol.19No. 2
Feb,2011
切向空气气流对激光烧蚀碳纤维复合材料过程的影响
陈敏孙，江厚满
（国防科学技术大学光电料学与工程学院，湖南长沙410073）
摘要：研究了靶材表面存在和不存在切向空气气流时，975nm连续激光对碳纤维增强树脂基复合材料的辐照效应。两种情况下靶材的动态响应过程明显不同，没有切向气流时，激光辐熙1.28s后，向外喷出的热分解产物在空气中燃烧，出现火焰同时伴有浓烟；有切向气流时，没有观察到带火焰和浓烟的燃烧现象，面是在激光辐照后的瞬间，激光作用区出现灼烧状亮斑，并间歇有少许颗粒向外喷出。分析认为，向外溢出的树脂基热分解产物会抑制氧气向靶材表面扩散，从面对碳纤维具有保护作用：切向气流的加载不仅会破坏热分解产物对碳纤维的保护作用，还会促使氧气到达碳纤维表面，进而导致碳纤维在较低的温度（约850℃)发生氧化烧蚀。
关
键调：激光辐照；碳纤维复合材料；切向气流；氧化烧蚀
中图分类号：TN249
文献标识码：A
doi,10.3788/OPE. 20111902.0482
Influence of tangential airflows on process of
laserablatingcarbon-fibercomposites
CHEN Min-sun, JIANG Hou-man
(College of Opto-electronic Science and Engineering:
National University ofDefenseTechnology,Changsha 410073,China)
Abstract: An experiment of 975 nm continuous wave laser irradiating carbon-fiber reinforced resin composites was studied, while the front surface of a target was with and without tangential airflow loadings, The results show that the dynamic responses are obviously different for two different cases, While the front surface of the target is without tangential airflow loading, the ejected inner pyrolysis products ignite surface combustion which is accompanied by dense smoke and flame after laser irradiation for I. 28 s, While the front surface of the target is with tangential airflow loading, there is not obvious combustion flame, but a burn-like bright spot is in the laser-irradiated zone and a little particles spll into the air intermittently. Analysis indicates that the out overflows of pyrolysis products will inhibit the diffusion of oxygen to the target surface, which has a protective effect on the carbon fiber. The presence of tangential airflow not only undermine the protective effect of pyrolysis products on the carbon fiber, but also promote the diffusion of oxygen to the surface. Therefore, the loading of tangential airflow will result in the carbon fiber suffered from oxidative ablation at the low temperature (850 C).
Key words: laser irradiation; carbon-fiber composite; tangential airflow; oxidative ablation
收稿日期：2010-10-08；修订日期：2010-10-30. 基金项目：国防科技基础研究基金资助项目