Influence of Ca-Ce/La synergistic alloying on the microstructure and mechanical properties of extruded Mg-Zn alloy

Compared with the sole Ca or Ce/La element, the Ca-Ce/La synergistic microalloying represents an excellent strengthening effect in extruded Mg-Zn alloy, which is mainly attributed to the grain refinement during the extrusion process. Ca-Ce/La addition results in the refinement of the secondary phases and precipitates, promoting the pinning effect for dynamic recrystallized grain growth and dispersion strengthening effect, which also contributes to the increased yield stress. Furthermore, Ca-Ce/La combined addition leads to the more uniform distributions of fine secondary phases, which can improve the ductility and promote the particle stimulated nucleation effect, resulting in a weak basal texture in extruded Mg-Zn alloy.