Shock Hugoniot and Mie-Gruneisen EOS of TiAl alloy: A molecular dynamics approach

Molecular dynamics (MD) simulations coupling multi-scale shock technique (MSST) are performed to study the shock Hugoniot and Mie-Gruneisen equation of state (EOS) for TiAl alloy. The accuracy of the EAM potential for TiAl is examined by both melting temperature at a free pressure and Hugoniot curve. The material composition seriously affects the linear relation of shock wave velocity and particle velocity, Hugoniot curve, and internal energy. The Born-Mayer potential and Morse potential both can describe the cold curve at lower compressions, while the cold curve described via the Born-Mayer potential is larger than that of Morse potential at higher compressions. The shock melting temperature (T-m) is totally determined by Gruneisen coefficient gamma, which shows an opposite trend as compared with the increasing T-m at the whole compressions. Mie-Gruneisen EOS presents a concave surface in pressure - specific volume - internal energy (P-V-E) space, which is independent of the reference curves utilized the cold curve and Hugoniot curve.