2001 Volume 42 Issue 2 Pages 215-219
The fabrication techniques using a droplet, which is formed at the nozzle tip of an injector-like crucible by pushing a melt from the crucible and a piston rod, is called “the suspended droplet method”. The changes of grain size, dendritic morphology and macrosegregation which dependent on the droplet size are investigated in high- and low-purity aluminum and Al–0.5 mass%Cu alloy. A single crystal might be formed in the high-purity Al when the droplet size becomes as small as 1 mm in diameter. As the purity of Al decreases, polycrystals are formed even though the droplet size decreases. The sample of Al–0.5 mass%Cu alloy shows coarse dendrites, which gradually degenerate as the droplet size decreases. Additionally, the profile of the Cu concentration becomes uniform as the droplet size decreases.