Spheroidization of primary α-Al phase in semi-solid A356 aluminum alloy slurry prepared by a serpentine channel was observed.The results show that amounts of fine gain-free and dendrite can be created in the under-cooling alloy melt in serpentine channel as a result of chilling effects of inner-wall

in which the majority is drifted to the central zone of serpentine channel and multiplied

and then parts of are evolved into spherical grains and dendrite by spheroidization and ripening

and other parts are grown into dendrite with large size