Effect of minor addition of Zn on precipitate crystal structures and intergranular corrosion in 6082 Al-Mg-Si alloys

Recycling Al alloys promotes greater sustainability, as the energy required to produce recycled alloys is only about 5% of that needed to produce the same amount of primary alloys. However, the build-up of impurities, such as Zn, during the recycling process can negatively affect the corrosion resistance of recycled alloys. The results show that the susceptibility to intergranular corrosion increased with minor additions of zinc (≤ 0.06 wt%). Zn was found to segregate along the grain boundaries, and the STEM-EDS results indicate that the Zn incorporates into the structure of Mg-Si containing grain boundary precipitates. • Minor Zn addition negatively influenced the IGC of Al-Mg-Si. • The presence of Zn in β increase the driving force for IGC. • 0.06 wt% Zn has a substantial influence on the precipitate structure of 6082 Alloy. • Zn does not tend to occupy specific columns in the precipitate structure.