Unveiling mechanisms and onset threshold of humping in high-speed laser welding.

ABSTRACT: The fabrication of fuel cells relies on a rapid laser welding process. However, challenges arise with the occurrence of humping when the welding speed surpasses a critical threshold, which poses difficulties in achieving a smooth surface finish and a consistent weld strength. This study aims to elucidate the humping mechanisms by analyzing the morphology of molten pool and the characteristics of melt flow at varying welding speeds via in situ synchrotron high-speed X-ray imaging and computational fluid dynamics simulations. Our findings indicate that the short keyhole rear wall, the high backward melt velocity, and the prolonged tail of molten pool are the primary factors contributing to the onset of humping. Furthermore, a dimensionless humping index ( πh ) was introduced, which successfu

SUBMITTER: Lai ZH 

PROVIDER: S-EPMC11538395 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature