Dissimilar joints of additive manufactured and wrought aluminium alloy produced by refill friction stir spot welding

With refill friction stir spot welding (RFSSW) solid-state joining of aluminium alloys, not weldable with fusion-based processes, is possible. Hence the process is used in this study to join AlSi10Mg, processed by laser powder bed fusion (LPBF), with high-strength wrought alloy AA7075-T6. Rotational speed was varied to investigate different heat inputs at constant plunge depth and welding time. The investigation showed the best mechanical properties and integrity for medium heat input joints, where the best balance between hook height and integrity was observed. The feasibility of RFSSW for joining AlSi10Mg with high strength wrought alloys was confirmed showing high potential for further investigations and industrial applications.