高脉冲重复频率小光斑激光扫描冲击渐进成形  

Scanning Laser Shock Incremental Forming Using Laser Beam with Both High Repetition Rate and Small Beam Diameter

作　　者：李健[1] 洪伟 吴晨翔 金卫凤[2] Li Jian;Hong Wei;Wu Chenxiang;Jin Weifeng(School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,Jiangsu,China;School of Mechanical Engineering,Jiangsu University,Zhenjiang 212013,Jiangsu,China)

机构地区：[1]江苏大学材料科学与工程学院,江苏镇江212013 [2]江苏大学机械工程学院,江苏镇江212013

出　　处：《应用激光》2023年第4期87-93,共7页Applied Laser

基　　金：国家自然科学基金(51775248)。

摘　　要：激光冲击成形是利用激光冲击波和凹模的限制作用实现膜材微纳结构制备的有效方法,近20年来得到学术界的广泛关注。目前广泛使用的激光冲击成形工艺中,激光光斑跨越数个微结构特征并且所使用的激光重复频率小于1000 Hz,这一方面使激光束所覆盖的各个结构受到的冲击波作用不均匀,另一方面低重复频率激光限制了激光冲击成形速度。为此,提出高脉冲重复频率小光斑激光扫描冲击渐进成形工艺用于微结构成形制造。采用脉冲重复频率为40 kHz、光斑直径为50μm的高脉冲重复频率小光斑激光冲击成形宽度为200μm、长度为6 mm的微槽结构,分析成形微结构的高度和微结构的截面形状随激光扫描范围的波动情况。结果表明,在激光扫描范围变动的情况下,成形微结构的高度较为稳定;在微结构的起始阶段和终止阶段,成形微结构的高度具有一定的过渡范围,终止阶段的过渡长度远大于起始阶段的过渡长度;所成形的微结构截面能够采用圆弧进行拟合。Laser shock forming is an effective method for preparation of micro and nano structures on foils by using laser shock wave and the confining effect of die,which has attracted extensive attention in recent 20 years.In most reports on laser shock forming process,there are two issues.The first issue is that the laser spot spans several microstructure features,which causes difference in shock wave over different features.The other issue is that the laser repetition rate used is less than 1000 Hz,which limits the speed of laser shock forming.In this paper,a laser with repetition rate of 40 kHz and spot diameter of 50μm were employed to form a groove with width of 200μm and length of 6 mm on an aluminum foil.The fluctuation of the height and crosssection shape of the formed microstructure in the laser scanning range were analyzed.The results showed that the height of the formed microstructure is relatively stable in the whole laser scanning range.There is certain transition in the height of the formed microstructure at the beginning and end of the microstructure,and the transition length of the end stage is much longer than that of the beginning stage.The formed microstructure crosssection can be fitted by circular arc.

关 键 词：激光冲击成形 高脉冲重复频率 小光斑 稳定性 

分 类 号：TN249[电子电信—物理电子学]