Corrosion behaviour of AA6082 Al-Mg-Si alloy extrusion: The influence of quench cooling rate

摘要

The influence of quench cooling rate on corrosion behaviour of AA6082-T6 Al-Mg-Si alloy extrusion is investigated. It is revealed that different quench cooling rates result in significant difference in grain boundary precipitation and intergranular corrosion (IGC) susceptibility. Transmission electron microscopy is employed to probe corrosion front with the aim of precisely determining the role of each individual grain boundary precipitate in IGC propagation. However, it is observed that Mg2Si precipitate doesn't significantly affect the process of corrosion propagation along the grain boundary and the presence of Cu-containing precipitates is not a necessary condition for IGC to occur in the alloy.