Equation of state for shock-compressed porous molybdenum from first-principles mean-field potential calculations

TL;DR

This study develops a first-principles mean-field potential method to accurately predict the shock response and Hugoniot properties of porous molybdenum, aligning well with experimental data especially at low porosity levels.

Contribution

It introduces a combined first-principles and mean-field approach to model shock compression of porous molybdenum, improving accuracy over previous models.

Findings

Excellent agreement with experiments at low porosity.

Accurate predictions up to 3.5 km/s particle velocity.

Overestimation of shock velocity at higher porosities.

Abstract

The Hugoniot curves for shock-compressed molybdenum with initial porosities of 1.0, 1.26, 1.83, and 2.31 are theoretically investigated. The method of calculations combines the first-principles treatment for zero- and finite-temperature electronic contribution and the mean-field-potential approach for the ion-thermal contribution to the total free energy. Our calculated results reproduce the Hugoniot properties of porous molybdenum quite well. At low porosity, in particular, the calculations show a complete agreement with the experimental measurements over the full range of data. For the two large porosity values of 1.83 and 2.31, our results are well in accord with the experimental data points up to the particle velocity of 3.5 km/s, and tend to overestimate the shock-wave velocity and Hugoniot pressure when further increasing the particle velocity. In addition, the temperature along the principal Hugoniot is also extensively investigated for porous molybdenum.