Dendritic solidification in undercooled Ni-Zr-Al melts: Experiments and modeling

摘要

The kinetics of dendritic solidification in a ternary Ni_(98)Zr_1Al_1 alloy is investigated experimentally in a range of melt undercoolings 40 K = 220 K, growth rates are decreased. Sharp-interface modeling predicts growth rates over the whole range of undercooling. Phase-field simulations give quantitative predictions for the dendritic growth velocity in the solute-controlled growth regime. Results show that the composition and temperature dependency of the thermo-dynamic data, e.g. liquidus slope and solute partition coefficient, are important for describing the alloys. Our findings give improved sharp-interface model predictions compared to calculations based on an approximation of the thermodynamic data derived from binary phase diagrams.