Elastic strain and texture evolution during tensile testing of peak-hardened Al–Mg–Si-profiles

Abstract

In situ high-energy synchrotron X-ray diffraction was used to investigate the deformation response of extruded Al–Mg–Si-profiles in the T6-temper condition. The profiles recrystallised completely during extrusion and were characterised by three distinct zones with a strongly textured and coarse-grained structure in the bulk region (br), while randomly oriented grains were observed closer to the surface. Despite these differences, through-thickness measurements of elastic strains revealed that work hardening is of the same order in the three zones, most likely due to the presence of particles introduced during the T6 heat treatment. Expansive strain normal to the profile surface was observed and explains the appearance of surface roughening. Finally, the degree of grain rotation was found to decrease, as particles reduce dislocation mobility in the grains.