*1.1. Background*

Aluminum alloys have recently increased their employment in different engineering fields, especially for transport, due to their excellent properties including good corrosion resistance, high strength, good formability, and low density [1–4]. The current main requirements of the automotive field such as the necessity of reducing emissions, the improvement of vehicle performance, and the preservation of safety targets [5–7] imply a further need to improve and study lightweight structures fabricated from aluminum alloys [8–10]. The manufacturing of complex shapes, where welded joints are usually required, is even more challenging.
