Ti-6Al-4V to over 1.2 TPa: Shock Hugoniot experiments, ab-initio calculations and a broad-range multiphase equation of state*

Titanium alloys are used in a large array of applications. In this work we focus our attention on the most used alloy: Ti-6Al-4V (Ti64). Here we present high-fidelity experimental shock compression data measured on Sandia's Z machine. We extend the principal shock Hugoniot for Ti64 to more than threefold compression, up to over 1.2 TPa. We use the data to validate our ab initio molecular dynamics (AIMD) simulations, and to develop a highly reliable, multiphase Equation of State (EOS) for Ti64, spanning a broad range of temperature and pressures. The resulting principal Hugoniot and the broad range EOS and phase diagram up to 10 TPa and 100000 K are suitable for use in shock experiments and in hydrodynamic simulations.