Constructing initial nanocrystalline configurations from phase field microstructures enables rational molecular dynamics simulation

摘要

The phase field method is used to create the nanocrystalline (nc) copper film with more physical and natural grain boundaries (GBs) for molecular dynamics (MD) simulation. The results show that the average flow-stress and ductility for the phase field model (PFM) is larger than that for the regular-hexagonal model (RHM) due to large fraction of twinning in the PFM during the tensile deformation. Multiple twins are generated by the evolution of stacking faults (SFs). But, the conversion rate (hexagonal-close-packed (HCP)-> twinning boundaries (TBs)) for the PFM is smaller than that for the RHM because the deformation can be mediated by the curved GBs of PFM to reduce the stress-concentration.