A Novel Ordered B2 Particle Strengthened Mg-Li-Zn Alloy

Mg-13Li-9Zn alloy is prepared by casting and hot rolling. The microstructure evolution and mechanical properties are systematically investigated by optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM), and tensile tests. A large number of B2 nanoparticles semicoherent with the matrix are uniformly dispersed within the grains of the as-cast Mg-13Li-9Zn alloy, which increases the hardness by three times compared with that of the as-cast Mg-13Li alloy. However, the continuously distributed MgLi2Zn phase at the grain boundary reduces the ability to resist tensile stress, resulting in intergranular fracture at the elastic deformation stage. After rolling, dynamic recrystallization occurs, and both the strength and ductility are improved. The B2 particles have good thermal stability and maintain a semicoherent relationship with the matrix during the hot rolling process. In addition, some spinodal decomposition zones are introduced into the matrix via the rolling process. The yield strength (YS) and elongation (EL) of the rolled alloy reach 280 MPa and 22%, respectively.