Crystal Plasticity Finite Element Modeling of Extension Twinning in WE43 Mg Alloys: Calibration and Validation

Crystal plasticity simulation is an important tool for advanced Integrated Computational Materials Engineering for metals and alloys. The current work presents a calibration and validation framework for crystal plasticity finite element (CPFE) simulation of extension twinning in the Mg alloy WE43 using the scanning electron microscopy with digital image correlation (SEM-DIC) technique. Rolled Mg alloy WE43 was subjected to in situ uniaxial compression along its rolling direction. Full-field displacement maps were captured using SEM-DIC during load pauses, and twin variant maps were obtained from the strain maps using post-processing analysis. CPFE was used to investigate the experimental results via a multi-scale twinning model developed for HCP polycrystals. In addition to macroscopic stress–strain curves, crystal plasticity parameters were calibrated using the variation of twin fraction area versus the applied strain obtained from the SEM-DIC results to accurately capture the twinning parameters. A new SEM-DIC pipeline was created for the open-source PRISMS-Plasticity CPFE software that can read in the precise deformation map generated by SEM-DIC as an input boundary condition for the finite element simulation and conduct the CPFE simulation. The performance of CPFE was evaluated versus the SEM-DIC obtained strain and twin maps. The results show that the CPFE can successfully model the macroscopic stress–strain response and the twin area fraction and that it can additionally capture microscale strain and twinning.