7000-series aluminum alloys are widely utilized in manufacturing critical components in automotive and aerospace industries. Fracture of brittle intermetallic particles is deemed as the genesis of fatigue failure in these alloys. Hence accurate representation of grains and intermetallic particles in virtual RVEs is of paramount importance for any subsequent fatigue crack modeling.
Employing a GA-based stereological method, high-fidelity 3D virtual two-phase microstructures are constructed based on 2D EBSD/SEM data. The proposed reconstruction algorithm respects morphological and crystallographic distributions of grains, morphology and two-point correlation function of particles, and particle-grain correlations. Detailed analysis is carried out to determine the size of microstructure-based statistically equivalent RVE (M-SERVE), the minimum RVE size where convergence in microstructural descriptors is achieved. A stabilized large-deformation finite element framework is then adopted to perform numerous crystal plasticity simulations to determine the size of property-based SERVE (P-SERVE), the minimum RVE size where convergence in micromechanical properties is attained. Comparing M-SERVE and P-SERVE, conclusions are drawn with respect to doing micromechanical modeling with representative volume elements.