Simulations on the growth of dislocation density during Stage 0 deformation in BCC metals

This study focuses on modelling the behaviour of single crystal tantalum in Stage 0 characterized by the large activity of edge dislocations and relative inactivity of screw dislocations. The multiplication of dislocation density is investigated using dislocation dynamics (DD) simulations and a dislocation density based continuum model of single crystal plasticity. The DD simulations are used to guide the constitutive development of the continuum model and to determine its material specific parameters. While not all of the material constants needed by the continuum model can be determined, due to the limited strain histories considered in the simulations, interpreting the DD simulations through a dislocation mechanics based continuum plasticity model allows for the efficient extraction of scaling laws controlling the growth of dislocation density.