Modeling of surface phenomena of liquid Al–Ni alloys using molecular dynamics

This work presents a study on the surface tension of liquid Aluminum–Nickel (Al–Ni) alloys. Obtaining adequate values of surface tension for this system is not a simple task as these alloys present the formation of atomic clusters with short-range order at certain compositions, which dramatically influences surface tension. The Compound Forming Model predicts the influence of these clusters on surface tension, but experimental limitations have obstructed its validation due to deficient thermodynamic data. This work attempts to overcome some of these limitations by using Molecular Dynamics (MD). By comparing the obtained results from MD simulations with those of an equivalent system without clusters, it was possible to infer the role of the atomic clusters on Al–Ni surface tension. It was found that these clusters increase surface tension by decreasing the Al content at the surface. They achieve this reduction in Al content at the surface by trapping Al atoms and hindering their travel to the surface.