Process limit imposed by the occurrence of undercuts during high-speed laser welding

High-speed laser welding is a very efficient process that results in weld seams of high quality. The process is limited by the occurrence of weld defects, such as humping and undercuts. It was found that a transition from a weld without defects to a weld with undercuts occurs when a speed limit is exceeded. It was also found that undercuts occur at slightly lower feed rates than humping. Thus, it was concluded that undercuts represent the upper process limit of high-speed laser welding and may be seen as the precursor of the humping regime.