Effects of Grain Size on Deformation Inhomogeneity of Hot-Deformed AA7075

The complicated and coupled effects between dislocation and dynamic recrystallization inducing deformation inhomogeneity and further damage in the hot plastic deformation process of 7075 aluminum alloy restrict the formability of thin-wall parts for new energy vehicles. In this paper, the influence of grain size on hot deformation inhomogeneity of 7075 aluminum alloy under uniaxial tension is investigated. Then, a multiscale dislocation density based crystal plasticity model is established by considering dislocation slip. After verification, the virtual polycrystalline RVE models with different grain sizes and representative crystal orientations were constructed and embedded into crystal plasticity simulation in DAMASK via spectral method. The simulation results show that with the increase of grain size, the von Mises stress and dislocation density decreases. By introducing a proportion of Cube, Goss and other recrystallization texture, the von Mises stress is 8 MPa lower than that of random crystal orientation at the same grain size.