Reshock response of Aluminum 1100 alloy

Reverse impact experiments were performed using a two-stage light gas gun to examine the reshock response of Al 1100 alloy. For this, bilayer impactors consisting of an Al sample and a high-impedance backing material (e. g. molybdenum) were impacted against <111>-oriented Gadolinium Gallium Garnet (GGG) windows. Upon impact, Al samples were first shocked to (or near) the solid-liquid mixed-phase region along the principal Hugoniot and then reshocked to a higher pressure. Measured reshock velocity, determined from the shock breakout times recorded at the Al/GGG interface using PDV probes, was used to obtain the pressure and density of the reshocked Al alloy with high precision. Our high-precision data enable us to explore the validity of the “reflection approximation” often employed during impedance matching. We will discuss our findings and compare them to EOS model predictions. LLNL-ABS-2002450