Experiments and crystal plasticity simulations on plastic an-isotropy of naturally aged and annealed Al–Mg–Si alloy sheets

The influence of the heat treatment on the plastic anisotropy of an Al-Mg-Si sheet was investigated. Uniaxial tension tests were conducted for T4 and O tempered Al-Mg-Si sheets. It is found that the in-plane variation of the R value, texture, and grain size are almost identical for both sheets. By contrast, the anisotropy of the flow stress is clearly dissimilar. The heat treatment alters the anisotropy of the flow stress. The plastic behaviors of the specimens were simulated using the crystal plasticity model. The orientation dependence of the flow stress is found to be sensitive to the dislocation interaction matrix. The flow stresses predicted by the interaction matrix determined based on the dislocation dynamic simulation agree with the experimental results for the O temper sheet. Whereas, this interaction matrix does not reproduce the flow stress anisotropy for the T4 temper sheet. The interaction matrix filled with unity results in the flow stress anisotropy similar to the experimental trend of the T4 temper sheet. In contrast to the flow stress, the R value is insensitive to the interaction matrix, and the predicted R values agree with the experimental results for both specimens.