Shock compression of porous metals and silicates

This paper reviews the results of experimental research on shock-compressed porous metals conducted in laboratory conditions and underground nuclear explosion environments. The general properties of shock adiabats are discussed. A rather simple wide-range equation of state is applied to describe the totality of test data. Porous metals and silicates are comparatively studied for, and found to qualitatively differ in, their behavior over a wide pressure range (tens of GPa). A possible explanation for the nonstandard behavior of silicates is that the Gr$\ddot{\rm u}$neisen coefficient in these states of matter can assume negative values at elevated pressures and temperatures. A similar anomaly is hypothesized to account for the superadiabatic density growth in the upper mantle of Earth.