Influence of dynamic recrystallization and shear banding on the localized corrosion of severely deformed Al-Mg-Si alloy
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2018 Acta Materialia Inc. The low intergranular corrosion resistance of extruded aluminum alloys is a limiting criteria for several applications. In this work, we investigated the effects of shear deformation, dynamic recrystallization and peak aging on the corrosion susceptibility of an AA6061 alloy up to seven ECAP passes following route Bc. We assessed intergranular corrosion susceptibility using the standard ISO test 11846 (Method B). Our results show that dynamic recrystallization improves the localized corrosion resistance of severely deformed AA6061 by reducing the fraction of shear bands in the material. We found a clear difference in surface reactivity between the recrystallized grains inside and outside the shear bands, suggesting that in this material grain-stored energy influences corrosion more than grain boundary precipitation. In parallel, we characterized the degradation of conventionally extruded AA6061-T6. The results reveal that shear deformation is a promising process for extruded aluminum alloys with improved strength and intergranular corrosion resistance.