民机蒙皮激光除漆工艺机理与关键技术

我国民航运输发展迅猛，民机蒙皮除漆需求剧增，目前蒙皮除漆以人工打磨与化学褪漆为主，可控性差，环境污染严重，亟待绿色自动化除漆技术。激光除漆具有绿色、高精度、易自动化等优点，但民机蒙皮激光除漆仍面临以下技术瓶颈：脉冲激光难以同时满足除漆效率与光纤传输要求、多物理场交互作用、基材损伤与质量控制。项目围绕激光除漆瞬态烧蚀气化、热膨胀应力及等离子体冲击波耦合作用的关键科学问题，提出双脉冲模式激光控制技术，获得能够强化等离子体冲击效应，且光纤传输的脉冲激光；分层次建立高重频纳秒激光瞬态烧蚀气化微-细观模型、温度-应力-冲击载荷耦合作用下漆层响应宏-细观模型及基材热力响应宏观模型，揭示激光除漆多尺度物理机制；开展民机蒙皮激光除漆多目标工艺优化与质量评估研究，建立多输入参数与除漆质量对应关系。项目研究成果将发展激光除漆基础理论，解决民机蒙皮激光除漆亟待突破的工程难题，提升我国民航自主维修技术核心竞争力。

Civil aviation transportation developed rapidly and the demand of paint removal of civil aircraft skins increased sharply. At present, the paint removal of civil aircraft skins is mainly based on manual sanding and chemical method, which have poor controllability and pollute the environment seriously. Thus, the pollution-free and automated paint removal technology is urgently needed. Laser paint removal has the advantages of pollution-free, high precision, and easy to automate, however, the following technical bottlenecks during laser stripping of civil aircraft skin need to be solved: it is difficult for pulsed laser to meet the requirements of paint removal efficiency and optical fiber transmission at the same time, interaction between the multiple physical effects such as transient ablation, thermal expansion stress, plasma shock wave during laser paint removal process, and the micro-damage of substrates and quality controlling. This project focuses on the key issues of the coupling mechanism of transient ablation, thermal expansion stress and plasma shock wave during laser paint removal process, the theoretical model and controlling method of the dual pulse mode laser is proposed to obtain a dual-pulse laser beam that not only strengthening the plasma shock effect but also could be transmitted by optical fiber; a micro-meso model of high-frequency nanosecond laser transient ablation, a macro-meso response model of paint layer under the temperature-stress-impact load, and a macro thermal-mechanical response model of substrate are established by scale to reveal the multi-scale physical mechanism of laser paint removal; multi-objective parameter optimization and quality assessment of laser paint removal of civil aircraft skin are carried out to establish a corresponding relationship between multi-process parameters and paint removal quality. Research results of this project will develop the theory of laser paint removal, sovle the engineering problems of laser paint removal of civil aircraft skin, and enhance the core competitiveness of our civil aviation maintenance technology.