Friction-stir, tailor-welded blanks made from primary and recycled 6082 aluminium alloys

Abstract

The use of aluminum is increasing in electric vehicles (EVs) owing to the high demand for weight reduction. Producing aluminum from recycled scrap requires 95 % less energy than primary metal production, which provides the potential to accelerate the transition to a carbon–neutral economy. In this research, we use Tailor-Welded Recycled Aluminum (TWRA) made of recycled and primary aluminum, aiming to understand the weldability with recycled materials and their potential use as automotive components. AA6082 produced by extrusion from primary and recycled materials, respectively, were welded by conventional Friction Stir Welding (FSW). The welding process was performed both in T4 and T6 temper conditions. Despite the undermatched characteristics relative to the base metal, the primary–recycled joints showed higher joint strength when welded in T4 condition and higher ductility when welded in T6 condition. SEM and EDS analysis revealed precipitate evolution, and intermetallic phases played a strong role in determining the mechanical behavior of these welded joints.