In-situ monitoring of Al/Cu dissimilar laser welding process using optical emission spectroscopy (OES)

• Published in: Optics and laser technology Vol. 176; p. 110893
• Main Authors: Kang, SeungGu, Shin, Joonghan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2024
• Subjects: Aluminum; Copper; Dissimilar laser welding; In-situ monitoring; Laser-induced plasma; Optical emission spectroscopy; Dissimilar laser welding; Optical emission spectroscopy; In-situ monitoring; Copper; Aluminum; Laser-induced plasma
• ISSN: 0030-3992
• DOI: 10.1016/j.optlastec.2024.110893

•Plasma was measured using optical emission spectroscopy (OES) during Al/Cu dissimilar welding process.•Welding state was classified into non-welding, threshold welding, and Cu-penetrated using plasma parameters.•A strong correlation between a weld geometry and the intensity of Cu emission line was found.•The potential of OES-based in-situ monitoring for Al/Cu dissimilar laser welding was demonstrated. Aluminum (Al) and copper (Cu) dissimilar laser welding is an in-demand process in the manufacture of secondary battery systems for electric vehicles. However, the absence of a robust in-situ monitoring technique for this process reduces its efficiency and increases the potential risk to the battery system. Laser-induced plasma (LIP) has been extensively studied in various laser processes because it provides crucial information regarding the interaction between the laser beam and material. In this study, the measurement of LIP was conducted using optical emission spectroscopy (OES) during the Al and Cu dissimilar welding process to gain a comprehensive understanding of the process. Moreover, the feasibility of OES as a monitoring tool for dissimilar laser welding of Al and Cu was evaluated. Plasma parameters such as emission line intensity, electron temperature, and number density were effectively used to diagnose the welding state (non-welding, threshold welding, or Cu-penetrated welding). In addition, a strong correlation between the weld geometry and intensity of the Cu emission line was found. This study demonstrates the considerable potential of OES-based in-situ monitoring system applicable for high-demand dissimilar laser welding processes.