A numerical study of the influence of crystal plasticity modeling parameters on the plastic anisotropy of rolled aluminum sheet

The production of stamped parts from rolled aluminum sheets requires different tempers and different thermal routes. While the slip and hardening behavior of the alloy strongly depends on the temper and the process temperature, the crystallographic texture remains largely static. Although the plastic anisotropy of rolled sheet is largely a function of the crystallographic texture, a dependency of plastic anisotropy on the temper has been reported for 6xxx series alloys, indicating that slip and hardening behavior have some influence. A systematic investigation of the effect of the slip and hardening behavior on the plastic anisotropy, however, does not exist. In this study, a crystal plasticity fast Fourier transform framework is utilized to predict the r-values, a common measure for plastic anisotropy, of two widely used commercial aluminum alloys possessing different crystallographic textures, AA6016 and AA5182. To investigate the sensitivity of the r-values to changes in the modeling parameters, a suite of simulations is performed in which the modeling parameters are systematically changed, and the resulting changes to the predicted r-values are calculated. Furthermore, numerical parameters, such as the level of discretization and the number of simulated grains are studied. Results indicate that the predicted r-value is less dependent on changes to crystal plasticity modeling parameters than to the initial crystallographic texture. Resulting trends are discussed.