Abstrakt
Metastable phases in form of planar defects are responsible for the top strength in many Mg alloys, especially with rare earth elements (RE) (Y included) and affect their corrosion. Orientation of these defects in the α-Mg matrix determines strictly their hardening effect.
Peak hardening in Mg-RE alloys is reached by dense triangular arrangement of prismatic plates, whereas basal plates have only a moderate effect on basal dislocations slip. The Zn addition in the alloys leads to a decrease of stacking fault (SF) energy and consequently to formation of variety of thin basal planar defects.
Moreover, Zn addition was proved to favourably influence corrosion and biocompatibility of some of these alloys (e.g. Mg2Y1Zn in wt. %).