Molybdenum plastic deformation: From large scale molecular dynamics simulations towards continuum dislocation dynamics

Molybdenum (Mo) is an important material for both practical and theoretical purposes. Very high melting of Mo (2896 K) on the one hand make it a promising structural material, on the other hand a wide pressure and temperature range of the BCC phase stability —provides wide simulational opportunities. It is, therefore, a good example for development and calibration of elastic-plastic models.

We perform large scale molecular dynamics simulations of uniaxial compression of Mo along [100] direction. Strain rates 10⁷-10⁹ /s are considered. Contribution of various hardening mechanism are studied with respect to various strain rates and temperatures to produce a continuum dislocation dynamics (CDD) model. We emphasize that this approach does not require experimental data. The CDD results are in good agreement with various shock-waves experiments.