“Measurements of weld quality with OCT during laser beam oscillation welding of aluminum alloy for battery production.”

Dr. Nataliya Deyneka Dupriez, Lessmüller Lasertechnik GmbH

Successful mass production is closely linked to a quality assurance procedure tailored to the joining process. The oscillating laser beam (laser welding optics) was used for welding aluminum alloy. Continuous weld depth monitoring was realized with OCT by synchronously controlling the position of the OCT scanner and the processing scanner optics. On the one hand, this ensured the required penetration, which benefits the stabilization of the molten pool and keyhole and thus better weld quality. On the other hand, control of the weld penetration depth is essential to avoid the risk of piercing the battery cell when welding the battery system. The variation of weld depth within the oscillation period was observed and analyzed in conjunction with video recordings. OCT enables highly accurate non-contact process monitoring and quality assurance during remote Laser welding optics and can serve as a corrective and/or preventive measure to achieve zero scrap and optimal battery performance without compromising safety.