Abstract
Eight different alloy powders, Al-14%Si, Al-4%Si, A1-4.5%Cu, Zn-22%Al, Sn-15%Cu, Cu-50%Zn, Zn-20%Sn and Zn powder, were atomized by a centrifugal atomization to observe the solidified structure. Excepting Zn and Cu-50%Zn, powders had equiaxed dendric structures. However, the secondary dendrite arm spacings of powders were different from the calculated ones by using Ranz-Marshall's equation. Zn particle had facetted surfaces composed of {00.1} plane, which is known to be formed to the direction of solid growth. These results suggested that undercooled solidification occurred instead of isothermal solidification from the surface.
