Abstract
Aluminium is increasingly adopted in large-scale structural applications due to its high strength-to-weight ratio, corrosion resistance, and excellent recyclability, making it attractive for automotive, aerospace, infrastructure, and renewable energy sectors. Despite these advantages, welding remains a major barrier to the wider use of aluminium in load-carrying structures. This challenge is particularly critical for precipitation-hardened 6xxx series aluminium alloys, where welding-induced thermal cycles can lead to significant strength degradation in the heat-affected zone (HAZ). Strength losses of up to approximately 50% may occur as a result of precipitate dissolution and coarsening. In addition, weld quality can be further compromised by defects such as porosity and lack of fusion. Laser-based welding has emerged as a promising alternative to conventional arc welding due to its high energy density and low overall heat input. These characteristics enable narrower HAZ, reduced distortion, and improved mechanical performance of welded joints, while also offering high productivity and potential cost reductions in the fabrication of large aluminium structures. This paper details industrial challenges, weldability limits, and the mechanisms of beam oscillation, which has emerged as a primary solution for stabilizing the keyhole, suppressing porosity, and refining microstructure. A case study has also been included in this paper to show the potential of laser oscillation in pore suppressing in hybrid laser-arc welding (HLAW) of 6082 aluminium.