The invention provides an Er-contained
magnesium alloy and a preparation method thereof. The Er-contained
magnesium alloy comprises the following components of, in percentage by atom, 0.2%-2.0% of Er,0.2%-2.0% of Y, 0.2%-2.0% of Zn and balance Mg and inevitable impurities. The method comprises the following steps of
smelting, homogenizing treatment, deformation and aging treatment. According to the
alloy and the method, the content the distribution in the
magnesium alloy of a long-period ordered
structural phase can be adjusted through the addition of the Er, and a precipitated phase can prevent a
basal plane from
dislocation glide, so that the strength of the alloy is improved; a LPSO phase and a magnesium matrix phase are in a coherency relationship, and the crack growth can be prevented, so that the
plasticity of the alloy is improved; the Er and the magnesium have similar atomic radii, and a good
solid solution strengthening effect is achieved by adding the Er in the Mg matrix; and W phases and the distribution of the W phases in the alloy can be effectively adjusted through addition of the Er, and the second phases all play
dislocation glide prevention roles, so that the
mechanical property of the alloy can be effectively adjusted and controlled through the addition of the Er.