Dynamic strength of tantalum under impact

Abstract

Two sets of plane impact experiments were carried out on tantalum targets (1-2 mm thick): shock re-shock and shock-rarefaction. Some of the experiments were with and some without a LiF window. VISAR diagnostics was used to measure free surface velocity or particle velocity. The VISAR information was utilized to study the equation of state and dynamic strength of tantalum under compression and tension. The Hugoniot pressures in the experiments were roughly 6, 13, and 34 GPa. Coupling between 1d hydrodynamic simulation and a calibrated Zerilli-Armstrong model reproduces the experimental results fairly well. Spall strength extracted from pull back velocity yields a relatively high value of 6.3-6.5 GPa with negligible pressure dependence.