A Review on Mg-RE Alloys with High Product of Strength and Elongation

Abstract

The combination of magnesium and rare-earth (RE) elements can produce the lightest constructional metals, i.e. Mg-RE alloys. These Mg-RE based alloys have been used in the fields of aerospace, electronics, communications, and automobiles, etc. However, most of the Mg alloys have been suffered from the “strength-ductility trade-off” phenomenon, which limits their applications. With the present of long period stacking ordered (LPSO) phases, the Mg-RE-X alloys usually exhibit high strength, high ductility and high creep resistance, and have drawn increasing interest due to their promising mechanical properties in the past two decades. This paper reviews the development of Mg-RE based alloys, proposes a concept of high “product of strength and elongation” Mg alloys, and three main issues to be solved in future, which are (1) formation and deformation mechanisms of different structural units within a single-crystal Mg grain; (2) strengthening and toughening mechanisms in polycrystal Mg alloys; (3) manipulation of different structural units to produce Mg alloys with high product of strength and elongation.

Keywords

• Mg-RE alloys
• product of strength and elongation
• LPSO phase
• structural units