摘要
利用纳秒脉冲光纤激光器去除2024铝合金表面环氧树脂底漆(EP)及聚氨酯面漆(PU)。设置不同的激光功率、扫描速度及脉冲频率等参数,深入开展激光除漆技术研究。通过表面残漆、烧蚀速率等评价指标表征不同激光参数的单因素影响规律,通过激光功率密度曲线进行工艺阈值探究。结果表明:不同漆层/基底体系完全除漆且不损伤基底的功率密度位于阈值T3(完全除漆阈值)和T4(基底损伤阈值)之间,激光吸收系数、烧蚀凹坑缺陷以及漆层/基底结合力三者之间的竞争导致除漆难度为白漆<绿漆<黄漆,PU<EP;完全除漆后的基底表面Sa(除漆表面粗糙度)和PVH(峰谷高度差)与原始表面存在微米级差异,可保证再喷漆工艺质量及漆料用量;基底层塑性变形、晶体结构变化及浅表层硬化,使得显微硬度和残余应力升高,材料力学性能得以改善。
Epoxy resin paint(EP)and polyurethane paint(PU)were removed from 2024 aluminum alloy surface by nanosecond pulsed fiber laser.Different laser power,scanning speed and pulse frequency were set,and the research on laser paint removal technology was deeply carried out.The single factor influence rule of different laser parameters was characterized by the evaluation indexes such as surface paint residue and ablation rate,and the laser power density curve was selected to explore the process threshold.The results show that the power density of different paint layers/substrate systems that completely remove paint without damaging the substrate is between the threshold T3(complete paint removal threshold)and T4(basal damage threshold).The competition among laser absorption coefficient,ablation pit defects and the binding force of paint layer/substrate leads to the difficulty of removing paint as white paint<green paint<yellow paint,PU<EP.The Sa(removed paint surface roughness)and PVH(peak valley height difference)of the substrate surface after complete removal of paint are different from the original surface in micron scale,which can ensure the quality of the repainting process and the amount of paint material.The microhardness and residual stress increase due to the plastic deformation,crystal structure change and surface hardening of the substrate,and the mechanical properties of the material are improved.
作者
郭达
陈亚军
杨雅婷
杜世兴
GUO Da;CHEN Yajun;YANG Yating;DU Shixing(School of Aeronautical Engineering,Civil Aviation University of China,Tianjin 300300,China;Sino-European Institute of Aviation Engineering,Civil Aviation University of China,Tianjin 300300,China)
出处
《热加工工艺》
北大核心
2026年第3期131-137,144,共8页
Hot Working Technology
基金
中国民航大学实验技术创新基金项目(2021CXJJ49)。
关键词
铝合金
激光除漆
激光功率密度
除漆阈值
残余应力
aluminum alloy
laser paint removal
laser power density
paint removal threshold
residual stress
