In situ X-ray diffraction measurement of shock-wave-driven twinning and lattice dynamics

Pressure-driven shock waves in solid materials can cause extreme damage and deformation. Understanding this deformation and the associated defects that are created in the material is crucial in the study of a wide range of phenomena, including planetary formation and asteroid impact sites^1,2,3, the formation of interstellar dust clouds⁴, ballistic penetrators⁵, spacecraft shielding⁶ and ductility in high-performance ceramics⁷. At the lattice level, the basic mechanisms of plastic deformation are twinning (whereby crystallites with a mirror-image lattice form) and slip (whereby lattice dislocations are generated and move), but determining which of these mechanisms is active during deformation is challenging. Experiments that characterized lattice defects^8,9,10,11 have typically examined the microstructure of samples after deformation, and so are complicated by post-shock annealing¹² and reverberations. In addition, measurements have been limited to relatively modest pressures (less than 100 gigapascals). In situ X-ray diffraction experiments can provide insights into the dynamic behaviour of materials¹³, but have only recently been applied to plasticity during shock compression^14,15,16,

Publisher URL: http://dx.doi.org/10.1038/nature24061

DOI: 10.1038/nature24061