Liquid cooling rate (
VLC), average cooling rate of solidification range (
VSC), temperature gradient (
G), moving rate of solid-liquid interface (
R) and
G/R were changed as solidification conditions. Structures of ingots are all equiaxed by presence of grain refining zirconium. The grain size is primarily affected by
VLC and decreases exponentially with its increase. With increasing
R and decreasing
G, the amount of Mg-RE-Zn eutectic compound increases. It crystallized along grain boundaries nucleating at boundary triple junctions. The morphology of the eutectic compound remains unchanged after a heat treatment for 5h at 215°C.
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