Abstract:

Fe82.5Ni17.5 alloys were undercooled by means of molten glass fluxing and cycling superheating methods. The maximum undercooling of 330 K was achieved. In combination of the theoretical calculations and experimental observations, the solidification behavior and structure formation mechanisms were systematically investigated. If the bulk undercooling ΔT<63 K, the coarsening dendritic structures result. When ΔT is in the range of 63 K<ΔT<158 K, influenced by the serious remelting, which is produced by recalescence, the primary dendrite is remelted into refined spherical crystals.

Key words: rapid , solidification,  ,  , grain , refinement,  ,  , microstructure,  ,  , Fe-Ni , alloy,  ,  , crystal , growth