Large elastic wave amplitude and attenuation in shocked pure aluminum

Shock-induced elastic-plastic deformation in pure aluminum was examined at 4 GPa peak stress by measuring wave profiles in thin (40-180 mu m) samples under plate impact loading. Unlike past work, large elastic wave amplitudes (similar to 1 GPa) and rapid elastic wave attenuation with propagation distance were observed. The combination of large elastic wave attenuation in thin samples and differences in sample thicknesses between the present and past work suggest a consistent picture of shock propagation in pure aluminum where time-dependent elastic-plastic response is confined to material very near the impact surface. The present results cannot be fully reconciled with recent shockless compression results.