Dynamic Measurements of the Al Melt Boundary

With the coupling of dynamic loading platforms with synchrotron light sources, shock melting has been shown to occur rapidly. Pyrometry is beginning to measure the melt line at high strain rates, providing data to compare to static measurements. However, there is limited information about density and kinetics along the melt line apart from shock melting. This talk will present results from shock-release experiments in pure Al shocked and release through states spanning 50-185 GPa. Velocity profiles measured at different sample thicknesses enable lagrangian analysis of release through the melt boundary and measurement on longitudinal wave speeds leading into shock melt. The results provide off-Hugoniot measurement of the melting phase transition leading into shock melting.