Predicting and confirming the solidification kinetics for liquid peritectic alloys with large positive mixing enthalpy

Those peritectic alloys with large positive mixing enthalpy usually display metastable liquid phase separation. Here, the solidification kinetics for a model Fe₅₀Cu₅₀ alloy in broad cooling rate R_c range was predicted by phase-field simulations and confirmed by drop tube experiments. Near-equilibrium peritectic solidification occurs in small R_c regime below 5.62×10² K s^-1. As R_c rises beyond 7.76×10² K s^-1, metastable phase separation takes place and results in the formation of a dispersed structure. Afterwards, multilayer core-shell structures appear, and the layer-number varies from two-layer to six-layer with further increasing R_c. Once R_c exceeds 3.64×10⁵ K s^-1, a dispersed structure once again forms because the core-shell dynamic condition is not satisfied. Non-equilibrium peritectic solidification is induced if R_c is greater than 5.85×10⁵ K s^-1.