Formability comparison of recycled and primary AA6082 alloy exposed to different heat treatments

The adoption of recycled aluminum alloys is crucial for sustainable lightweight automotive design, yet quantitative assessments of their sheet formability remain limited. This study compares the mechanical properties and formability of primary AA6082–P and recycled AA6082–R alloys under three temper conditions: soft annealed (A), solution-treated W-temper (WT), and naturally aged T4 (3 weeks). Compared to AA6082–P, AA6082–R contains higher levels of impurity elements, particularly Fe (0.30 vs 0.22 wt%) and Cu (0.22 vs 0.0025 wt%), while main alloying elements (Mg, Si, Mn, Cr) remain comparable. Uniaxial tensile tests showed that the transverse direction exhibited the highest strength, with T4 and A conditions increasing yield strength (YS) and ultimate tensile strength (UTS) by ∼1.5× compared to WT. For AA6082–P in the ED orientation, YS increased from 102.5 (WT) to 195 MPa (T4), while UTS rose from 155 to 310 MPa; fracture strains increased ∼10% in T4 and A conditions. AA6082–R displayed similar trends with slightly lower strength but comparable ductility. Square cup drawing revealed the greatest localized thinning particularly in AA6082–P (∼2× higher corner thinning than AA6082–R), while T4 specimens achieved higher limiting drawing depths and more ufniform thickness. Soft annealed samples exhibited moderate formability due to incomplete microstructural evolution. Overall, recycled AA6082–R demonstrates tensile and forming performance comparable to primary AA6082–P across all tempers, supporting its application in lightweight sheet-forming processes without significant performance loss.