Equilibrium thermodynamic theory for the evaluation of temperature distributions in overdriven steady-plane wave fronts

Abstract

Temperature distributions in overdriven steady wave fronts in solid 2024 Al shocked up to 80 GPa, in which no melting occurred in the wave fronts, were evaluated using the equilibrium thermodynamic theory. The effective strain increments were sufficiently small and the effective temperature rise times were sufficiently long with respect to electron–phonon relaxation times to justify using equilibrium thermodynamics. In addition, the sufficiently large viscous-stress components supported the efficacy of the thermodynamic theory. The same is true of shocks up to 250 GPa in solid Pt and 230 GPa in solid Fe. Furthermore, the influence of viscous stress was examined by evaluating the temperature distributions for inviscid 2024 Al, Pt, and Fe solids using the equations for temperature derived from the Mie–Grüneisen equation. Finally, we demonstrate that there might be a solid–liquid–solid Hugoniot between the solid and liquid–solid Hugoniots for Fe and estimate the solid–liquid–solid and liquid–solid Hugoniots.