飞秒激光不锈钢表面陷光微结构的制备与性能研究

摘要

The stainless steel surfaces were microstructured with a two-step femtosecond laser in high vacuum environment,and antireflection capability in a wavelength range of 200-900 nm was investigated.The micro-structures of the stainless steel surfaces were studied by the scanning electron microscopy and the X-ray diffrac-tion.In the first scanning with high laser fluence,periodic spikes on micron scale covered with typical laser-in-duced periodic surface structures (LIPSS)were obtained.The sample was then rotated 90°,and the second scanning was performed with laser fluence of 0.02J/cm2 intersecting the first treated region.With this two-step laser cross scanning method,the double-scale structure namely micron spikes covered with submicron particles were obtained on the stainless steel surface.The reflectance tests showed that the average reflectance of the double-scale structure was about 2.28%,which was only approximately equal to 3.42% of that of the polished stainless steel surface.Chemical analysis by X-ray diffraction indicates that blackness of stainless steel surfaces was attributed to the microstructures formed by femtosecond laser instead of the change in elemental composi-tion.%利用飞秒激光在高真空环境下，在316L 不锈钢表面两次交叉扫描制备了周期性微纳结构，并研究了微纳结构对波长范围200~900nm 的光波的吸收增强能力。样品表面微结构形貌与成分采用扫描电子显微镜(SEM)和 X 射线衍射仪测试。第1次扫描采用高能流激光，获得了微米级锥状钉结构，表面覆盖了典型的激光诱导周期性表面结构(LIPSS)。然后将样品旋转90°，采用能流为0.02J/cm2的激光进行第2次扫描，路径与第1次扫描相交。第1次扫描的结构中的LIPSS被第2次低能流激光打断纳米颗粒，从而与锥状钉结构结合形成双尺度微结构。反射率测试结果表明，这种双尺度微结构表面的平均反射率约为2.28%，为光滑表面平均反射率的3.42%。结合XRD分析结果，不锈钢表面获得强陷光性能主要归因于飞秒激光制备的微结构。