Effect of yttrium on the microstructure of a semi-solid A356 Al alloy

The semi-solid slurry of an A356 Al alloy, which was grain-fined by yttrium, was manufactured by low temperature pouring. The effects of grain-refining on the morphology and the grain size of the primary α phase in the semi-solid A356 Al alloy were researched. The results indicate that the semi-solid A356 Al alloy with particle-like and rosette-like primary α-Al can be prepared by low temperature pouring from a liquid grain-refined A356 alloy. The grain size and particle morphology of primary α-Al in the A356 Al alloy are markedly improved by the addition of 0.5 wt.% Y. The fining mechanism of Y on the morphology and grain size of the primary α-Al in the semi-solid A356 Al alloy was delved.