Melting behind the front of the shock wave

Abstract

A simple caloric model of the equation of state is proposed to describe thermodynamic properties of solid materials with phase transitions with the minimum number of parameters as initial data. Thermodynamic characteristics are calculated in the wide range of densities and pressures. The equation of state of the solid phase was modified by introducing configurational entropy, which made it possible to describe a liquid medium by the same functional dependence, but with its initial parameters. This allowed us not only to construct the equation of state for the liquid, but also to determine the dependence of the melting point on pressure as the boundary between the phases with the corresponding state. It is shown that the melting process is practically not noticeable on the shock adiabat in the pressure - volume plane; however, sharp adiabatic breaks are observed in the temperature - pressure plane. The calculated position of the melting curve agrees with the experimental data found; although this does not fully justify the conclusion about the accuracy of the calculation of the liquid phase adiabat, but fully confirms the qualitative picture.