High strength Mg-Zn-Y alloys containing quasicrystalline particles

High strength Mg-rich Mg-Zn-Y(-Zr) alloys, strengthened by quasicrystalline particles, have been developed by thermomechanical processes. The deformation behaviors of these alloys at room and high temperatures have been investigated and compared to those of commercial alloys AZ31, AZ61 and AZ91. Yield strengths of the Mg-Zn-Y alloys, which increase with an increase in the volume fraction of quasicrystalline phase, are relatively high due to the strengthening effect of quasicrystalline particles. At high temperatures (300 - 425°C), the flow stress levels of the Mg-Zn-Y alloys are lower than those of AZ31, AZ61 and AZ91, while their elongations to failure are larger. Quasicrystalline particles in the Mg-Zn-Y alloys resist coarsening during deformation at temperatures up to the eutectic temperature, leading to a stable distribution of quasicrystalline particles. Stability of both quasicrystalline particles and microstructure of the α-Mg matrix in the Mg-Zn-Y alloys provides large elongation with no void opening at the interface between the quasicrystalline phase and the α-Mg matrix.