Effect of microstructure on the deformation of as-cast α-Mg/LPSO two-phase alloys: An integrated SEM-DIC and crystal plasticity study

The present work investigates the plastic deformation of as-cast Mg/LPSO two-phase alloys with varying LPSO phase volume fractions through a combination of SEM-DIC and CPFE simulations. To this end, the same microstructures observed experimentally were numerically deformed and the predicted strain fields were compared to the experimental ones. The reasonable agreement between the simulations and the experiments confirmed that basal slip in LPSO grains is the prevalent deformation mechanism. Besides, analysis of the experimental strain field in LPSO grains suggested that the relevant length scales governing the strength of basal and non-basal slip in LPSO grains were the LPSO length parallel to the basal plane and the LPSO width perpendicular to it. Finally, discrepancies in terms non-basal slip activity were suggested to be due to an overestimation of the strength of prismatic slip combined with the omission of first-order pyramidal slip in the modeling hypotheses. This study sheds light on the complex interplay between microstructure and deformation mechanisms in Mg/LPSO two-phase alloys. It emphasizes the importance of considering multiple slip modes and accurate CRSS values when modeling such systems. Additionally, it highlights the valuable insights that can be gained through a combination of experimental and computational approaches in understanding localized strain behavior.