Numerical simulation and process parameter optimization of laser spot welding for ultra-thin sheets

This study investigates laser spot welding of a 0.06 mm thick spring layer baseplate onto a thin substrate, employing numerical simulation via Simufact Welding(2020 version). Validation of the numerical model revealed a strong agreement between simulated and experimental molten pool diameters, with a minimal deviation of 5.8 %. The optimal welding strategy for a single feather-shaped component demonstrated that fixtures reduced post-weld deformation by ∼60 %, albeit with a 20 % increase in residual equivalent stress. Through an L9 (3³) orthogonal experiment, laser power, cooling time, and welding time were identified as critical parameters influencing deformation, with the optimal combination being 20 W laser power, 1.8 s welding time, and 30 s cooling time. Furthermore, welding sequence analysis showed that a counterclockwise approach minimized deformation by 36 % compared to the clockwise sequence, while orthogonal sequences reduced deformation by 28 % relative to conventional methods. These results offer practical insights for enhancing the dimensional stability and mechanical performance of ultra-thin component welding.