Semisolid Casting of Short Freezing Range Alloys

摘要

Semisolid casting and non-dendritic solidification of commercially pure tin (about 1 °C freezing range) and Zamak 3 alloy (about 10 °C freezing range) by a modified serpentine channel method were studied. It was shown that semisolid casting of very small freezing range metals with a non-dendritic structure was possible using this method. The results showed that the wall of the copper serpentine channel mold acted as a substrate for heterogeneous copious nucleation of primary solid particles and the channel provided sufficient self steering action to disperse the nuclei in the melt. The average diameter and shape factor of the primary particles in the semisolid cast CP-Sn sample was measured to be about 107 μm and 0.75, respectively. The average diameter and shape factor of the primary particles in the semisolid cast Zamak 3 alloy was measured to be about 16 μm and 0.8, respectively. Hardness of semisolid samples was slightly higher than those of conventional gravity cast samples.