Zusammenfassung
Laser welding of high-strength aluminum alloys at high feed rates leads to transverse hot cracks. These cracks present a
major challenge for electromobility applications, especially in the manufacturing of battery cases, as transverse hot cracks
can lead to a leaky weld seam and potential component failure. To determine suitable strategies for the avoidance of
transverse cracks, their formation was experimentally investigated and theoretically analyzed. A simulation of the
temperature field and the fluid flow in the melt pool showed a decrease of the static pressure at the liquidus isotherm at
high feed rates. The decrease of the static pressure in the melt pool impairs the liquid feeding between the solidifying
grains and increases the risk of transverse hot cracking. To balance this pressure drop in the melt, a mechanic compressive
stress was applied on the sample during welding. Such stresses are present in case of welding e.g., rollforming profiles.
The resulting welds show a significant reduction of transverse cracks which highlights the potential of applying external
mechanical compressive stress to reduce the formation of transverse hot cracks.
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