Strain and texture evolution of ED-rotated cubes during quasi-static and dynamic tensile testing of Al–Mg–Si-profiles in the as-extruded T1-temper condition

High-energy synchrotron X-ray diffraction has been used to study through-thickness deformation response in extruded Al–Mg–Si-profiles during tensile testing, in terms of micro- and mesoscopic distributions and dynamical evolution of elastic strains and grain rotations. Local averaging with analysis at intermediate length scales reveals strongly inhomogeneous through-profile elastic strains, caused by the presence of three distinct microstructure regions and the compatibility relations that apply at their interfaces. Variations in elastic strains at characteristic microstructure lengths are found to be large; typically 1σ Gaussian spreads for the different ɛij-components of the elastic strain tensor are minimal and of the order 1.0 × 10−3 in the central profile region at low stresses. The spread increases with the tensile loads, but even more dramatically with decreasing distance to the surfaces where maximum 1σ spreads up to 6–7 × 10−3 are encountered. The evolution and distribution of certain texture components have been analysed, showing grain rotations to be a non-negligible part of the deformation response that activates at quite modest plastic deformations. Inhomogeneous strain response at local and intermediate length scales together with the strain and texture component relations that apply across the microstructure region boundaries are found to be decisive to surface roughening. All together, the results point in the direction that strain and texture evolution should be considered together in order to provide a more complete description of microstructure mechanics in metals.