Investigating effects of microstructural changes on microscopic strain field of high-pressure Die-Casting Al-Si alloys via RVE modeling

Heterogenous microstructures of High-Pressure Die-Casting (HPDC) Al-Si alloy lead to random strain concentrations during deformation. Different microstructural variations are considered, including Fe-rich phase and porosity, with focuses on different geometrical aspects. Representative Volume Element (RVE) models were established based on Electron Back Scatter Diffraction (EBSD) data using Finite Element Method (FEM). The effectiveness of the RVE models was verified by comparing predicted strain concentration locations with experimental results. The microstructural models were refined to explore effects of microstructural changes. The simulation results show that there is an interactive effect of porosity and Fe-rich phase on the microscopic strain field. When there is no porosity, the geometric properties of Fe-rich phase play an important role in changes of microscopic strain field. When average diameter of porosity is close to that of Fe-rich phase, position and shape of porosity dominate the microscopic strain field compared with that of Fe-rich phase.