高重频飞秒激光加工碳纤维复合材料的热影响研究

Thermal Effects of High-frequency Femtosecond Laser Processing of CFRP

碳纤维增强复合材料(Carbon Fiber Reinforced Plastics,CFRP)的激光定量去除是航空航天工业中结构修复的关键技术。然而,CFRP中碳纤维和环氧树脂性能的巨大差异使得激光加工非常具有挑战性,热损伤一直是CFRP激光加工广泛应用的主要障碍。为了研究高重频飞秒激光加工对CFRP复合材料的热影响,采用单因素实验方法进行了理论分析和实验验证,分析了激光能量密度、扫描速度和扫描方向对材料烧蚀速率与热影响区的影响规律,并研究了飞秒激光在CFRP上的高精度选区定量去除工艺。结果表明:当工艺参数选择θ=90°,脉宽为290 fs,功率为7 W,频率为100 kHz,扫描速度为300 mm/s,扫描间距为60~80μm时,整体烧蚀表面质量较优,精度(粗糙度)可以达到10μm,去除区域表面热影响区约为33.9μm。

Laser selective quantitative removal of CFRP represents a key technology for structural repair in the aerospace industry.However,the huge difference in properties between carbon fiber and epoxy resin in CFRP makes laser processing very challenging,and thermal damage has always been the main obstacle to the widespread application of CFRP laser processing.In order to study the influence of femtosecond laser processing parameters on the machining quality of CFRP,theoretical analysis and experimental verification were carried out by single factor experimental method.The influence of laser energy density,scanning speed and scanning direction on the ablation rate and the width of heat affected zone were analyzed,and the high-precision selective quantitative removal process of femtosecond laser on CFRP was investigated.The results show that when the process parameters are chosen to beθ=90°,pulse width of 290 fs,power of 7 W,frequency of 100 kHz,scanning speed of 300 mm/s,and scanning spacing of 60~80μm,the overall ablation surface quality is superior,and the accuracy(roughness)can be as high as 10μm,and the heat-affected zone(HAZ)on the surface of the removed area is about 33.9μm.