Multiple mechanisms of thermally activated plastic flow in shocked and unshocked tantalum

We argue that the principal features of the plastic flow behavior of tantalum can be described by a model that incorporates a two-component Peierls-type mechanism and an {open_quotes}obstacle{close_quotes} mechanism in series. We compare the results of calculations based on such a model with flow data for unalloyed tantalum before and after shock loading to 38 GPa for 1 {mu}s. Our data suggest that the shock loading changes only structural parameters.