Abstract:First-principles energetics calculations were performed over a group of 25 candidate elements, to investigate their partition energies and behaviors among major nano-phases (δ？-Al₃Li, θ？-Al₂Cu, T₁-Al₆Cu₄Li₃ and S-Al₂CuMg) in most commercial Al-Cu-Li-Mg alloys. It was revealed that principal alloying element Li cannot directly affect θ？ and S, Cu cannot directly affect δ？, Mg cannot directly affect θ？ and δ？ but can weakly partition into T₁. As for micro-alloying elements, Si is the only element that can partition into all the four nano-phases. Au can partition into δ？, θ？ and S. Cd can partition into δ？, T₁ and S. Zr can partition into δ？ and T₁. Ni substitution can weakly partition into θ？ and S. Ti, V, Zn, Ag and Mo can partition into δ？ only. Cr, Mn, Fe and Co cannot directly affect any of the four nano-phases. Almost all RE-elements can strongly partition into T₁, δ？ and S, but would be expelled by θ？. Only Sc is somehow particular to S, showing no partition preference in S. The newly obtained fundamental results could constitute a simple prototype database in support for the accelerated design of Al-Li based alloys and other related Al alloys.

Key words: Al-Cu-Li-Mg alloy; nano-phase; micro-alloying; solute partition; first-principles