Microstructure and properties of Mg–5.21Li–3.44Zn–0.32Y–0.01Zr alloy

Mg–5.21Li–3.44Zn–0.32Y–0.01Zr alloy was prepared. And the microstructure of as-cast and extruded specimens was analyzed with OM, XRD, SEM and TEM. Results showed that the specimens are composed of α phase, β phase, W phase and Mg0.97Zn0.03 compound. After extruding process, the microstructure is refined and the precipitated phases are broken into small particles and distribute uniformly in the matrix along the direction of extrusion. Mechanical properties results showed that the strength and elongation are both improved after extruding deformation. XRD analysis revealed that the element Y brought about the formation of W-phase in the alloy. The phase-forming mechanism in Mg–Li–Zn–Y–Zr alloys is not in agreement with that in Mg–Zn–Y or Mg–Zn–Y–Zr alloys.