Experimental and theoretical studies on a Mg2InRE-type prismatic precipitate plate in a series of Mg-In-RE ternary alloys

Abstract

In precipitation-hardening Mg-In-Sm alloy, a category of novel Mg2InSm prismatic plates have been built successfully and its crystal structure and atomic coordination were studied by atomic scale high-angle annular dark-field scanning transmission electron microscopy. The Mg2InSm plate has an orthorhombic structure, whose stability can be verified by first-principles calculations. Similarly, with the substitution of other rare earth (RE) for Sm, a series of Mg2InRE orthorhombic structures are also predicted to be stable. The findings are expected to guide the future design of effective precipitation strengthening phases in Mg–based alloys.