高能脉冲激光清洗形成非晶纳米晶改性层的机制与基体表面性能调控研究

High-energy pulsed laser cleaning is a frontier and hotspot in current laser cleaning research，currently, the path to optimization of traditional laser cleaning processes is based on evaluation of cleaning efficiency and cleanliness, without comprehensive consideration of the surface modification problem. Focus on the phenomenon of amorphous nano-crystalline high-performance surface sporadic formed by high-frequency high-energy laser cleaning, multi-factor polymerization excitation characteristics of physical impact, thermal aggregation, wave vibration on multi-parameter and multi-field coupling laser cleaning interface will be explored , the mechanism of laser cleaning the surface of the substrate to form amorphous nanocry-stalline modified layer will be revealed, And the formation of regulation-induced design criteria for the modified layer will be proposed, further, the formation of the amorphous nanocry- stalline modified layer on the cleaned surface transitions from “occasional” to “controllable”; Simultaneously, the path of process parameters for traditional laser cleaning will be braked, . important considerations of the modification of the surface in laser cleaning threshold determination will be inclusion, creatively constructing a new comprehensive evaluation system for laser cleaning effectiveness with "clean-high performance" synergies for surface cleaned, the synchronous improvement of the cleaning surface performance and the cleaning process level will be achieved . and then, a good foundation for optimizing and perfecting the theory and technology system of high-energy laser cleaning will be solid laid.

高能脉冲激光清洗是当前激光清洗研究领域的前沿和热点，当前，传统激光清洗工艺优化路径是基于清洗效率和清洁度的评价，未综合考虑被清洗表面改性问题。针对高能激光清洗偶发性形成非晶纳米晶改性层的现象，通过探究多参数多场耦合的激光清洗界面物理冲击、热聚集、波振等多因素聚合激发特征，揭示激光清洗基体表面形成非晶纳米晶改性层的机制，掌握激光清洗基体表面形成非晶纳米晶改性层的调控诱导方法，并建立形成该改性层的调控诱导设计准则，使改性层的形成由“偶发性”过渡到“可控性”；此外，突破传统激光清洗工艺参数优化路径，将被清洗表面改性纳入激光清洗阈值确定的重要考量，创造性构建被清洗表面“清洁-高性能”协同的新型激光清洗效能综合评价体系，实现被清洗表面性能和清洗工艺水平的同步提升，进而为优化完善高能激光清洗的理论与技术体系奠定坚实基础。

本课题针对航空铝合金蒙皮漆层激光清洗过程中基体表面形成非晶纳米晶改性层的现象，围绕既定的高能脉冲激光清洗的主导机制确定与基体表面多因素聚合激发作用、非晶纳米晶改性层的形成机制与行为规律、改性层的激光清洗参数调控诱导与表面“清洁-高性能”评价3个方面研究内容，通过3年多时间的深入研究，课题研究目标已经按计划完成，获得了诸多进展、成果和突破：.（1）表征了激光清洗产生的气态物质，澄清了其分子组成和化学结构，明确了被清洗基体表面光、声、热、等离子体等多因素聚合激发作用，确定了激光烧蚀、等离子体、激光直冲等不同清洗动力源的主导激光清洗机制。.（2）以基体表面组织成分、微观结构、应力状态和晶型特征的表征为基础，阐释了激光清洗形成非晶纳米晶层的机制和行为规律，并进行了系统性工艺优化；掌握了被清洗表面产生残余应力的规律和消控残余应力的手段，实现了表面清洁与基体性能同步强化的调控诱导。.（3）全面揭示了清洗工艺参数背后所蕴含的界面力学特性、激光延余能与热辐射等交互作用下表面改性行为相关机理，构建了激光清洗后基材表面内应力与激光清洗参数的关系，明确了金属基体表面残余应力与表面性能提升的关系，建立了基于灰度法的激光清洗铝合金表面漆层的评价路径，提供了一种考量被清洗表面改性状态的新型激光清洗评价方法。.（4）严格按照计划获得国家专利授权6项，发表论文9篇，SCI（EI）检索6篇，立项国家标准1项，主编出版激光清洗领域著作1部。.此外，面向某新型战机铝合金蒙皮漆层、航空发动机叶片表面积碳进行了基础工艺探索，已完成1000余片航空发动机叶片的激光清洗作业，激光清洗技术已列入某型战机大修漆层清洗技术规范。.总体而言，课题研究达到既定研究目标，为激光清洗蒙皮表面“清洁-高性能”协同的工艺参数优化调控提供了方法途径，为推进激光清洗技术向航空领域应用奠定了坚实基础。