Molecular-Dynamics Study Melting Aluminum at High Pressures

The dependence of the melting temperature versus the pressure under static conditions and under shock-wave compression of aluminum was calculated by molecular-dynamic modeling technique. The Morse potential and EAM potential (embedded atom method) was used for the interatomic interaction for the solid and liquid phases of aluminum. The calculations show a change of crystal structure of aluminum close to the melting range static compression and compression in the shock wave. Melting point was determined by analysis of the radial distribution function and the standard deviation of the atoms with the visualization of crystal structure. The results of molecular dynamics calculations are consistent with experimental data on the compressibility of the shock wave up to 200 GPa. Static melting results are consistent across the field of experimental data up to 30 GPa. A short-term compression in the shock wave, accompanied by the increase of entropy can be leads to overheating nonequilibrium substances. Under these conditions, the melting temperature under static and shock compression may be different from each other. However, the calculations showed on pressure in the shock wave 122 GPa aluminum melting occurs at temperatures close to the melting temperature in static conditions.