X-Ray diffraction evidence for the role of stacking faults in plastic deformation of solids under shock loading

Abstract

A mechanism responsible for the high speed shear relaxation immediately behind shock fronts is suggested. The shear stress generated by the shock front causes the growth of two-dimensional defects in the crystal lattice, known as stacking faults (SF). Increasing the SF concentration and area leads to the absorption of impact energy. A breach of the lattice symmetry due to the SF presence causes an additional shift in peaks of the x-ray diffraction pattern obtained from the shock compressed material. Thus pulse x-ray diffraction is the only method that experimentally measures both the dilatational and deviatoric components of the deformation, which takes place during shock wave passage.