Shock wave compression and release of hexagonal-close-packed metal single crystals: Inelastic deformation of c-axis magnesium

To understand inelastic deformation mechanisms for shocked hexagonal-close-packed (hcp) metals, shock compression and release wave profiles, previously unavailable for hcp single crystals, were measured for c-axis magnesium crystals. The results show that the elastic-inelastic loading response is strongly time-dependent. Measured release wave profiles showed distinct peaked features, which are unusual for inelastic deformation during unloading of shocked metals. Numerical simulations show that pyramidal slip provides a reasonably good description of the inelastic loading response. However, {101¯2} twinning is needed to explain the unloading response. The results and analysis presented here provide insight into the relative roles of dislocation slip and deformation twinning in the response of shocked hcp metals.