*2.2.5 Yttrium Y*

Generally, the addition of Yttrium (Y) aims to improve elevated temperature plasticity and the creep resistance of Mg alloys. Wu et al. [37] studied the mechanical properties of pure Mg and binary Mg-Y alloys. They demonstrated that the elongation is proportional with the Y content, but the strength decreases. Adding Yttrium to Mg-Zn alloys is effective to weaken and change the basal texture of wrought Mg alloys [38].

When added to the cast alloy ZK60, the mechanical properties and ductility are enhanced at elevated temperature. This is ascribed to the formation of ternary Mg-Zn-Y phase with high thermal stability [39]. Meanwhile, alloys containing yttrium are expensive.
