Two phases separate growth in directionally solidified Fe–4.2Ni alloy

A two phases separate growth microstructure is observed in directionally solidified Fe–4.2Ni alloy in diffusive regime. This structure consists of peritectic two solid phases, both of which grow with plane fronts in the pulling direction and occupy half width of the sample. A simple model was proposed to explain the formation of the separate growth structure in Fe–Ni alloy. It implies that the separate growth structure forms under predominantly diffusion-limited conditions and when the two phases grow steadily and independently in different solute fields.