Effects of Al and Y Addition on Microstructures and Mechanical Properties of As‐Cast Mg–14Li Based Alloy

In this study, effects of Al and Y contents on microstructural evolutions and mechanical properties of the as‐cast Mg–14Li alloy are investigated. The results show that Mg–14Li– x Al ( x  = 1, 2, 3 wt%) alloys are characterized by predominantly single β –Li and MgLiAl 2 phases. Slight refinement of β –Li grains is obtained with the increasing of Al content. The increased Al addition greatly improves the hardness, ultimate tensile strength, and yield strength of the Mg‐14 base alloy, accompanied by a significant reduction in ductility. Meanwhile, with addition of minor Y (0.5 wt%) addition leads to the introduction of homogeneous distribution of Al 2 Y particles in the Mg–14Li–3Al alloy, which plays a positive role in the strength enhancement. However, the uneven distribution of apparently coarsed Al 2 Y particles contributes to a significant reduction in tensile strength as the Y content is increased up to 1 wt%.