First-Principle Investigation of the Interface Properties of the Core-Shelled L1(2)-Al3M (M = Sc, Zr, Er, Y) Phase

The interface structure and segregation behavior of L1(2)-Al3M (M = Sc, Zr, Er, Y) phases were investigated based on first-principles calculations. The results showed that the order of the thermodynamically stable interface was Al3Zr/Al > Al3Sc/Al > Al3Er/ Al > Al3Y/Al. The interfaces of Al3Sc/Al3Zr, Al3Er/Al3Zr, and Al3Y/Al3Er obtained negative interfacial energies and low coherent strain energies and were favorable to form a clear interface. Zr atom tended to segregate to the first atomic layer on the Al side of the Al/Al3Sc, Al/Al3Er, and Al/Al3Y interfaces. The driving effect of the Zr atom segregation to the Al3Y shows was stronger than that to Sc and Er atoms, whereas the high coherent strain energy hindered the formation of Al3Y/Al3Zr interface. Er atom tended to segregate at the Al/Al3Y interface and accelerated the formation of core-shelled Al3Y/Al3Er. Furthermore, the formation of the double core-shelled Al3Y/Al3Er/Al3Zr was discussed.