Benchmarking autogenous core-ring static beam shaping and wire-fed laser welded EN AW-6360 extrusions: mechanical and microstructure properties

Laser beam shaping has significantly advanced laser beam welding in recent years, opening new opportunities for autogenous welding of 6xxx Al-alloys. Despite extensive literature, few studies have directly compared core-ring static beam shaping technologies with state-of-the-art wire fed systems. Addressing this gap, this work evaluates the mechanical and microstructural properties of welds produced in the newly developed EN AW-6360 alloy. Welds with filler wire demonstrated the highest tensile strength (142 MPa, 81% weld efficiency), attributed to enhanced nucleation and improved thermal regulation of the molten pool. In contrast, autogenous welds with a core only beam showed the lowest strength (101 MPa, 57% efficiency). Improvements were observed at a higher core to ring power ratio of 2.75, which refined the grain structure and resulted in a strength of 130 MPa (74% efficiency). The resulting grain size was within 14% of that achieved with filler wire. Redistribution of laser intensity promoted finer, more equiaxed grains and increased the fraction of high-angle grain boundaries. Filler-wire welds also exhibited the highest Mg 2 Si precipitate area fraction (1.24%), compared to 0.24% and 0.25% for the core only and core to ring welds, respectively, correlating with the strength increase. Overall, the results show that laser beam shaping effectively tailors grain morphology and solidification dynamics in 6360 Al-alloy welds; however, precipitation strengthening remains primarily governed by alloy composition and cannot be substantially modified through beam shaping alone.