Microstructures of Mg–Zn–Nd alloy including small quasicrystalline grains

Two kinds of Mg-rich and low neodymium Mg–Zn–Nd alloys including icosahedral quasicrystal phase (I-phase) were prepared under conventional casting conditions. The microstructures and phases of Mg–Zn–Nd quasicrystal alloys were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The results indicate that the I-phase in Mg–Zn–Nd quasicrystal alloy is a simple icosahedral quasicrystal with quasi-lattice of aR = 0.525 nm. It has been proved that the as-cast Mg70.8Zn28Nd1.2 quasicrystal alloy mainly consisted of I-phase and Mg7Zn3 matrix phase. While the as-cast Mg70.5Zn28.5Nd1 alloy mainly consisted of I-phase, Mg7Zn3 matrix phase, dendrite α-Mg phase and a new rod-like hexagonal phase.