Influence of near-surface embossing on the hot crack formation during laser beam welding of metal sheets from 6000 aluminum alloys
Maximilian Bachmann, Kim Rouven Riedmüller, Johannes Michel, Christian Hagenlocher, Mathias Liewald, Thomas Graf
Abstract. During laser beam welding of aluminum alloys, the formation of transverse hot cracks in the weld seam represents a critical issue that can substantially impair the mechanical strength and quality of welded joints. These cracks are initiated as a result of thermal deformation, the decrease of the static pressure in the melt pool and the shrinkage during solidification. Particularly, this affects alloys of the 6000 series with elevated concentrations of the alloying elements silicon and magnesium. In [1], authors have demonstrated that applying external mechanical compressive stresses during welding reduces the formation of transverse hot cracks due to an increase of the static pressure in the melt pool. However, since such compressive stresses cannot always be applied externally, it would be desirable to induce these stresses within the sheet metal material. Against this background, near-surface embossing [2] was used in the present study to induce compressive residual stresses in sheet metals. Simulations were first carried out to examine the effects of varying the distances between the embossed patterns and the weld seam area to determine whether the compressive stresses affect the welding zone. Subsequently, several configurations of embossed sheets were produced, analyzed and welded. Finally, the resulting hot cracks were analyzed using metallographic sections and the results were compared with unembossed welded samples. The comparison of embossed and unembossed samples revealed the amount of residual compressive stresses and thus the formation of hot cracks can be reduced depending on the distance and design of the embossing pattern. This proves embossing to be a valid method for inducing compressive residual stresses into sheet metal and thus to reduce the formation of hot cracks during welding
Keywords
Embossing, Laser Beam Welding, Hot Cracking, Residual Compressive Stresses
Published online 5/7/2025, 8 pages
Copyright © 2025 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA
Citation: Maximilian Bachmann, Kim Rouven Riedmüller, Johannes Michel, Christian Hagenlocher, Mathias Liewald, Thomas Graf, Influence of near-surface embossing on the hot crack formation during laser beam welding of metal sheets from 6000 aluminum alloys, Materials Research Proceedings, Vol. 54, pp 1221-1228, 2025
DOI: https://doi.org/10.21741/9781644903599-133
The article was published as article 133 of the book Material Forming
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
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