Metastable phase separation of Fe₅₀Cu₅₀ hypoperitectic alloy under space simulation conditions

A 3 m drop-tube was used to investigate the solidification of Fe₅₀Cu₅₀ hypoperitectic alloy. The falling droplets solidify as spheres and splats. The obtained particles range from 1000 μm to 80 μm in diameter. It was found that the phase separation occurs if the FeCu liquid is undercooled to a certain extent before solidification. In the big particles macroscopic separation of Fe-rich phase always appears in the center of the particles, and in the small ones the Fe-rich phase usually solidified as little spheres. In the flakes the Fe-rich and Cu-rich layers alternatively display from top to bottom.