First-Principles study on the nucleation of precipitates in ternary Al alloys doped with Sc, Li, Zr, and Ti elements

The nucleation phenomenon of the precipitates with L1(2)-type of ternary Al-rich alloys with Sc, Li, Zr, and Ti elements was studied using first-principles density functional calculations. We calculated certain properties that are closely related to nucleation behavior: surface energy, adhesion work, interfacial energy, segregation energy and interfacial charge transfer. Research indicates that Al (or Al(3)Z) (0 0 1)/Al(3)Z (0 0 1) (Z = Sc, Li, Zr, and Ti) with minimum interfacial energies nucleate and grow effectively. The critical Al(3)Z radii were calculated via the Gibbs free energy for homogeneous nucleation. The heterogeneous nucleation mechanism of Al(3)Z (0 0 1) substrates were characterized via wetting angles. A core-shell structure can form between any two of the four precipitates, which can verify the observed nucleation results in this experiment.