A through-process modelling approach of aluminium heat-affected zone softening and weld joint performance

Abstract Arc welding is one of the main joining processes of aluminium and its alloys. In general, Al-alloys are challenging to weld due to high heat conduction, susceptibility to porosity and solidification cracking. For precipitation-hardened alloys such as AA6082-T6, the heat-affected zone (HAZ) loses significant strength due to precipitation dissolution and coarsening, that result in almost 50% of strength reduction. To optimize the component strength after welding, the designers need to compensate with extra material as well as minimizing the heat input and the extension of the HAZ. In this procedure, appropriate heat input must be chosen which is controlled by welding parameters. Often, this may take several experimental runs and extensive post-welding investigations. Such an experimental approach becomes time-consuming and inefficient, especially if the geometry of the structure is non-uniform. As a solution, numerical modelling of the softening issue may boost design efficiency. Despite many studies of softening in AA6082 welds, there is still a need for robust and cost-efficient through-process modelling methods for such engineering cases. This work will demonstrate a consistent numerical approach for estimation of HAZ softening and weld joint performance and demonstrate its fracture resistance capability.