Strain localisation in solution heat treated Al–Zn–Mg alloys

Two Al–Zn–Mg alloys with recrystallised and fibrous grain morphologies are studied with regards to the microstructure after solution heat treatment, cold water quenching and immediate room temperature deformation. It was found that the dislocation movement was localised in narrow slip bands cutting through the dislocation tangles. This observation is related to dynamic strain ageing and to macroscopic shear bands frequently observed in these alloys.