Development of a mid-fidelity modelling approach for laser welding with novel beam shapes for electric mobility materials

Laser welding has become a key manufacturing process within the electric mobility industry, encompassing various components ranging from battery systems to body structures composed of Al-alloys and Cu-alloys. In this paper, a mid-fidelity model offers a viable approach to assist in defining parameter ranges for subsequent experimental campaigns, thereby reducing overall time and costs. This research aims to identify the minimum requirements for a time-efficient and adequately accurate numerical model tailored for parameter selection in laser welding processes. A mid-fidelity modelling platform is developed based on these criteria, capable of simulating laser welding processes utilizing both conventional Gaussian-like and novel ring-shaped beams. The model demonstrates sufficient accuracy in predicting bead shapes, particularly with beam intensity distributions relevant to 6XXX series Al-alloys and a key tool to study defect formation such as cracks formation. Furthermore, the platform's effectiveness is evaluated through the welding of Cu hairpins, providing insights into the transient behaviour during bead formation and the final weld shape. This study involves research on sensitivity analysis methods, comparison of different physical model selections, and parameter selection for mid-fidelity model. Finally, the adaptability of the simulation model was verified through welding experiments. This research not only presents a robust modelling approach for laser welding processes but also contributes to the understanding of complex phenomena in keyhole deep penetration welding, offering valuable insights for industrial applications.