Stress relaxation and precursor delay in laser shock-loaded iron

Pulsed lasers were used to induce plane shocks of short duration in iron samples of different thicknesses. Polymeric piezoelectric transducers were used to collect transmitted wave measurements. Findings indicated a decrease of the elastic precursor amplitude with increasing propagation distance and a stress relaxation behind the elastic wave front. Significant twin formations were found by postshock examinations of recovered specimens.