Heterogeneous flow and brittle failure in shock-compressed silicon

We combine a recently developed high-resolution two-dimensional (2D) imaging velocimetry technique (velocity interferometer system for any reflector (VISAR)) with 1D VISAR measurements to construct a moving picture of heterogeneous deformation in shock-compressed single crystal silicon. The 2D VISAR takes an intensity snapshot of target velocity and reflectivity over a mm field-of-view while the compression history is simultaneously recorded by the 1D VISAR. Our data show particle velocity surface roughening due to the anisotropic onset of plasticity and, above similar to 13 GPa, a structural phase transformation. Shock arrival at the Si free-surface is characterized by the formation of fracture networks and incipient velocity jetting. (C) 2013 AIP Publishing LLC.