超窄间隙激光均匀液态熔滴填充组织及性能调控机制研究

Aimed at the problems such as low laser power efficiency, high probability of defect formation and serious deformation of the component in laser welding process with filler metal, a uniform liquid droplet transfer technology based on Additive Manufacturing method is provided, by which the weld organization and component performance can be well regulated to improve the weld quality. In this paper, the interaction between the laser beam and the uniform liquid droplet, dynamic behavior of the uniform liquid droplet transfer process are studied, and thus the uniform liquid droplet transfer mechanism is clarified to realize a stability control of the weld process. The defect formation mechanism and Suppression method, molten pool flowing behavior and heat transfer mechanism, the component organization, residual stress and deformation evolution rules are also investigated, and therefore the welding joint organization of ultra-narrow gap laser welding process and the weld performance regulation mechanisms are acquired. The achievements of this project can optimize the weld quality of ultra-narrow gap laser welding process, and also broaden the application range of this welding process, which have significant engineering applications prospect.

针对厚板铝合金构件超窄间隙激光填丝焊过程，激光利用率低、缺陷及构件变形严重等问题，提出了基于增材制造技术的均匀液态熔滴填充方式，通过对构件焊接组织及性能的调控，有效提高焊接质量。项目将研究激光和均匀液态熔滴的相互作用机理、均匀液态熔滴熔入的动态行为，明晰均匀液态熔滴的熔入机制，实现焊接过程的稳定性控制。研究基于均匀液态熔滴填充方式的焊接接头缺陷产生及抑制机制，研究熔池流动行为及热质交换耦合机制，阐明组织、残余应力及变形的演变规律，从而获得超窄间隙激光焊接接头组织及性能调控机制。本项目不仅能优化超窄间隙激光焊接质量，并且可以拓展其技术应用范围，具有重要的科学意义及工程应用前景。

针对厚板构件超窄间隙激光填丝焊过程，激光能量利用率低、易产生缺陷及构件变形严重等问题，本项目提出基于增材制造技术的均匀液态熔滴填充方式，通过对构件焊接组织及性能的调控，有效提高焊接质量。项目对激光和均匀液态熔滴的相互作用机理、均匀液态熔滴熔入的动态行为进行了研究，明晰了均匀液态熔滴的熔入机制，实现焊接过程的稳定性控制。研究基于均匀液态熔滴填充方式的焊接接头缺陷产生及抑制机制，对熔池流动行为及激光与材料间的热质交换耦合机制进行了分析，阐明了熔滴过渡方式对接头缺陷形成的影响，通过控制均匀液态熔滴过渡，达到了对焊接接头缺陷的有效控制。项目基于超窄间隙激光焊接接头组织及性能调控机制，对超窄间隙激光焊接接头组织、主控因素与力学性能的关系、残余应力及服役性能进行了研究，阐明组织与性能的演变规律，并使用均匀液态熔滴激光填充焊得组织均匀细小、性能良好的焊接接头。本项目不仅对超窄间隙激光焊接质量进行了优化，并且可以拓展其技术应用范围，具有重要的科学意义及工程应用前景。