The Mg-5Zn-1Y-0.6Zr alloys were prepared by rapidly solidified method.Solidification structure and properties of the prepared alloy were investigated by XRD

SEM

HRTEM and micro-hardness measurements.Microstructure of the alloy is composed of fine α-Mg phase

amorphous phases and I-Mg3Zn6Y quasicrystal phase discontinuously distributes along crystal boundary.Based on the heat transfer theory

the cooling rate of the alloy ribbons can be calculated by one-dimensional heat conductivity equation.With the increase of cooling rate

grain size in the microstructure of the alloy is refined with the more homogeneous distribution of composition

and the volumetric fractions of amorphous phase are raised

meanwhile

micro-hardness value of the alloy is increased greatly

and the maximum value reaches Hv 167

which is 2.2 times of that of the conventionally solidified alloy.