Schematic of laser ablation experiment for dynamic loading.
Cross-section of recovered sample, showing columnar grains at the ablated surface. The sample was a single crystal of NiAl. The uniform dark gray area along the left edge is void.
Ablated surface of recovered sample showing rough texture with surface cracks. The sample was a single crystal of NiAl.
Regions of state space accessible with different irradiance histories.
Schematic of experimental configuration used for laser-driven isentropic compression experiments.
Schematic of experimental configuration used for ellipsometry measurements.
Ellipsometry signals during shock breakout in Sn, which occurs at after the start of the laser drive. Drive pressure gave on release into the LiF window: sufficient to induce melting. (TRIDENT shot 14 972.)
Example wide-angle diffraction data, obtained from a Ti crystal cut parallel to the (0001) plane and loaded to 6.9 GPa by laser ablation of a CH layer, at the JANUS laser facility.
Schematic of experimental configuration used for diffraction measurements from polycrystalline samples.
Example results from polycrystalline diffraction experiment on a rolled Be foil thick. Drive pressure was . Broad diffraction line spans a range equivalent to in isotropic strain or in uniaxial strain. The flow stress in Be foils deduced from velocimetry was .
Example experimental data from imaging displacement interferometer: NiAl bicrystal, field of view, frames at intervals after shock breakout. Large black blob is an ink alignment mark. If surface was flat, fringes would be straight and uniform. Included crystal near the center can be seen from its relative displacement; surface waves are also visible originating at the grain boundary as ripples in the lower frame.
Phase diagram of Be, showing principal Hugoniot, Lindemann melt curve, and effective melt locus under nanosecond-scale loading, predicted using SESAME (solid) and Steinberg (dashed) equations of state.
Velocity history for different thickness of Be sample during isentropic loading: experiment and simulations using different equations of state. The curves correspond to (from the left) no Be (i.e., the Al/LiF interface), Be, and Be.
Free surface velocity history for Be: (0001) crystal compared with rolled foil. Shock pressure was GPa.
Free surface velocity history for Be (0001) crystal: experiment compared with elastic-plastic model using microsecond-derived parameters (low amplitude) and flow stress increased to match the initial elastic precursor peak in the experiment.
Free surface velocity history for Be (0001) crystal: ablative loading experiment compared with microstructural plasticity model. Simulation used a spall stress of .
Article metrics loading...
Full text loading...