y 向搭接率对铝合金表面复合漆层激光清洗的影响  

Effect of y-direction Overlap Rate on Laser Cleaning of Composite Paint Layer on Aluminum Alloy Surface

作　　者：张天刚 段俊杰 刘天翔 侯晓云 张志强 Zhang Tiangang;Duan Junjie;Liu Tianxiang;Hou Xiaoyun;Zhang Zhiqiang(School of Aviation Engineering,China Civil Aviation University,Tianjin 300300,China)

机构地区：[1]中国民航大学航空工程学院,天津300300

出　　处：《中国激光》2023年第16期122-133,共12页Chinese Journal of Lasers

基　　金：国家自然科学基金(U2033211);中央高校基本科研业务费重点项目(3122022104)。

摘　　要：采用纳秒脉冲光纤激光器对2A12铝合金基材表面丙烯酸聚氨酯复合漆层进行了激光清洗实验,研究了不同y向搭接率(ηy)对除漆效果的影响。结果表明,当ηy为0和20%时,面漆全部去除,底漆部分去除;当ηy=40%时,仅少量底漆残留,大部分氧化膜被破坏,基材显露;当ηy=60%时,复合漆层全部去除,基材烧损。研究发现,随着ηy值逐渐增大,清洗表面烧蚀现象明显增加,漆层烧蚀气化将导致面漆着色剂和功能氧化粒子脱漆沉积于烧蚀凹坑表面;清洗表面残余漆层形成了凹坑-间隔-凹坑的清洗特征,表明清洗过程中烧蚀-等离子冲击(屏蔽)-烧蚀交替进行,烧蚀与等离子冲击作用均会对清洗表面产生热影响,导致残余漆层丙烯酸树脂链段自由基发生位置重排,同时诱发残余漆层产生热应力除漆机制;激光等离子冲击和热应力破坏是导致清洗表面残余漆层碎裂分层或物理剥离的主要原因。Objective The service environment of composite paint layer on civil aircraft skin is severe,making local and overall paint removal become necessary steps for routine maintenance of civil aircraft.Currently,manual grinding and chemical stripping are main technical means for paint removal of civil aircraft.Manual grinding is inefficient and easy to damage aircraft skin.Although chemical stripping has higher efficiency,the serious waste pollution can not meet increasingly stringent environmental protection requirements.Therefore,laser cleaning technology with low cost,high efficiency and minimal pollution has entered vision fields of researchers.However,the interaction and coupling effects among ablation,plasma shock(shielding),and thermal stress mechanisms during the cleaning have not been deeply understood at present.In this paper,effects of different laser overlap rates in y direction on cleaning quality are investigated using high-repetition-rate pulsed fiber laser cleaning system.By analyzing macro-micro morphological characteristics and composition changes of cleaned surface,mutual effect and coupling behaviors of different paint removal mechanisms and thermal degradation principle of residual paint layer are elucidated.We hope that the above researches can provide theoretical and experimental support for industrial application of laser-cleaned aluminum alloy composite paint layer.Methods In this paper,the laser cleaning experiment of composite paint layers of 2A12 aircraft aluminum alloy is performed using the high-repetition-rate pulsed fiber laser complete processing equipment under process conditions of four different laser overlap rates in y direction(ηy=0%,20%,40%,60%).Firstly,optical microscope(OM)is used to observe the states of cleaned surfaces and sections.Then,morphological characteristics of macro-and micro-structures as well as compositions and element contents on cleaned surface are further investigated by scanning electron microscope(SEM)and energy dispersive spectrometer(EDS).Furthermore,Fouri

关 键 词：激光技术 激光清洗 铝合金 复合漆层 y向搭接率 除漆机制 

分 类 号：TN249[电子电信—物理电子学]