In the search for materials suitable for additive manufacturing, knowledge of the thermophysical properties is very important but often difficult to access. Experiments measuring the diffusion and viscosity of molten metals such as titanium are very hard to conduct and have produced scattered data. Given those complications, even though classical molecular dynamics simulations have agreed with the experimental data, further support is desirable. This can be provided with ab initio molecular dynamics within the density functional theory framework. By explicitly considering the electronic structure problem, the forces on the atoms are expected to be very accurate at the cost of drastically increased computation time needed and far more restricted system sizes. Ab initio molecular dynamics simulations have already produced admirable results for aluminum near the melting point and these methods are being extended to titanium and titanium-aluminum alloys. Furthermore, the ab initio molecular dynamics data can be used to construct classical potentials through the use of a method called force matching. This allows for the use of classical potentials made specifically for molten metals.
Supported by the National Science Foundation through cooperative agreement OIA-1541079 and the Louisiana Board of Regents.