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实验中采用的切割系统如图 1所示。系统采用EdgeWavePX200-2-GM型皮秒激光器,通过3维扫描振镜实现z方向动态聚焦,使用空气作为辅助气体,并通过气刀作用于工件表面,气体压力为0.8MPa[16],实验采用超景深3维显微镜观测扫描深度和热影响区。
切割系统使用的激光波长为1064nm,脉宽为10ps,最大平均功率为100W,重复频率为0.4MHz~20MHz,通过3维扫描振镜聚焦后光斑直径为50μm,振镜最高扫描速率为20m/s。切割系统具体参量如表 1所示。
Table 1. Processing parameters
parameters value average power P 30W~100W repetition rate frep 0.4MHz~20MHz scanning speed vs 0.1m/s~20m/s pulse duration τ 10ps focus diameter d 50μm wavelength λ 1064nm -
实验中采用碳纤维复合材料,其增强体为碳纤维T300,基体为环氧树脂,各占50%,属正交层合板(碳纤维铺层的铺设方向为0°和90°),板厚为1.5mm,材料组成成分及热力学性能如表 2所示。
Table 2. Thermal and physical properties of the CFRP composite
parameters type carbon-fiber T300 epoxy resin density ρ/(kg·m-3) 1.78 1.1 evaporation temperature Tv/K 4000 700 structure damage temperature Td/K 3100 440 heat conductivity κ/(W·m-1·K-1) 50 0.1 specific heat capacity c/(J·kg-1·K-1) 710 1884 -
实验方法如图 2所示。将1.5mm厚CFRP板置于激光焦平面上,分别研究平均功率、扫描速率、重复频率、扫描次数对热影响区及扫描深度的影响。为了更加均匀地去除整个碳纤维复合材料和提高去除效率,对轨迹进行多次循环扫描,并通过动态聚焦系统实现焦点补偿。在切割中为了避免切缝过窄造成的遮蔽效应,扫描若干条间距为Δd的平行轨迹来增加切缝宽度,最终实现1.5mm厚CFRP切割。
碳纤维复合材料皮秒激光切割工艺研究
Research of carbon fiber reinforced plastic cut by picosecond laser
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摘要: 为了研究100W皮秒激光对碳纤维复合材料(CFRP)切割工艺,采用单因素实验方法,进行了理论分析和实验验证,得到了平均功率、重复频率、扫描速率、扫描次数对热影响区及扫描深度的影响规律,并对1.5mm厚碳纤维复合材料板进行了切割实验。结果表明,选取平均功率为60W、重复频率为0.4MHz、扫描速率为10m/s、轨迹重复扫描20次、切缝上表面宽为350μm等适当参量时,得到的直线切缝和圆形切孔的热影响区极小。这为皮秒激光切割CFRP的进一步研究与工业应用提供了参考。Abstract: In order to study the process of cutting carbon fiber reinforced plastics (CFRP) with 100W picosecond laser, theoretical analysis and experimental verivication were carried out by vaying a single affeting factor. Effect of average power, pulse repetition rate, scanning speed and number of repeat on the heat affected zone and scanning depth were studied. A piece of 1.5mm thick CFRP was cut in experiments. The results show that the cutting line and circular hole with almost no heat affected zone were obtained under the conditions of average power 60W, repetition rate 0.4MHz, scanning speed 10m/s, number of repeat 20 and upper surface width of the kerf 350μm. The study provides some reference for further academic research and industrial application of picosecond laser cutting CFRP.
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Table 1. Processing parameters
parameters value average power P 30W~100W repetition rate frep 0.4MHz~20MHz scanning speed vs 0.1m/s~20m/s pulse duration τ 10ps focus diameter d 50μm wavelength λ 1064nm Table 2. Thermal and physical properties of the CFRP composite
parameters type carbon-fiber T300 epoxy resin density ρ/(kg·m-3) 1.78 1.1 evaporation temperature Tv/K 4000 700 structure damage temperature Td/K 3100 440 heat conductivity κ/(W·m-1·K-1) 50 0.1 specific heat capacity c/(J·kg-1·K-1) 710 1884 -
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