Mg Segregation atAl/Al3ScHeterophase Interfaces on an Atomic Scale: Experiments and Computations

Abstract
Microscopic factors governing solute partitioning in ternary two-phase Al-Sc-Mg alloys are in- vestigated combining three-dimensional-atom-probe (3DAP) miscroscopy measurements with first- principles computations. 3DAP is employed to measure composition profiles with subnanometer-scale resolution, leading to the identification of a large enhancement of Mg solute at the coherent � -Al=Al3Sc (fcc=L12) heterophase interface. First-principles calculations establish an equilibrium driving force for this interfacial segregation reflecting the nature of the interatomic interactions.