Stress dependence of elastic-wave attenuation in LiF

Abstract

Shock‐wave propagation studies along the 〈100〉 direction in LiF single crystals are presented for three elastic impact stresses, namely, 39, 29, and 15 kbar. Present results demonstrate a stress threshold for a large increase in plastic strain rate and establish stress relaxation as a bulk property. Analysis of the data reveals a one‐to‐one correspondence between plastic strain rate and stress at the elastic‐shock front. This is in agreement with the constitutive relation generally used for stress‐relaxing solids under plate‐impact loading.