Investigations on opportunities and challenges of brilliant high-power laser beam welding with 24 kW and adjustable power distribution for different materials
Journal of Laser Applications
4
36
042063-1-042063-9
2024
Type: Zeitschriftenaufsatz (reviewed)
Abstract
Solid-state laser beam sources offer the possibility of generating high-brilliance laser beams with low expansion and high usable intensity at
the focal point. New approaches include beam shaping with the use of core and ring fiber and, therefore, variable power distribution in the
laser beam focal point and material interaction area. Particularly, high-power laser beam welding benefits from beam shaping because of the
stabilizing effect on the weld pool. Furthermore, the technical progress achieved with regard to beam quality also allows one to achieve high
Rayleigh lengths and, therefore, a more uniform beam diameter over the whole material thickness. In this study, investigations on highpower
laser beam welding with a 24 kW disk laser beam source are conducted for three different materials (mild steel, aluminum alloy, and
copper), which are of high interest for welding in different sectors. The influence of power distribution between the core and the ring as
well as welding speed on weld geometry (depth and width), weld pool stability, and the resulting weld seam quality is investigated. It is
shown that the welding process cannot just be scaled up in comparison with welding with lower laser beam power but has its own
challenges. It is possible that high welding depths (12mm for copper, more than 12mm is possible for aluminum, and 25mm for mild
steel) could be achieved in one pass. To achieve this, aluminum needs the lowest energy per unit length per mm of sheet thickness and
copper the highest.