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

✍ Scribed by P.K. Galenko; S. Reutzel; D.M. Herlach; S.G. Fries; I. Steinbach; M. Apel

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 548 KB
• Volume: 57
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/j.actamat.2009.08.043

✦ Synopsis

The kinetics of dendritic solidification in a ternary Ni 98 Zr 1 Al 1 alloy is investigated experimentally in a range of melt undercoolings 40 K 6 DT 6 320 K. The growth velocity is measured for samples processed by the electromagnetic levitation technique using a highspeed video camera. With DT K 220 K the measured growth rates are the same as those of a binary Ni 99 Zr 1 alloy. In the regime of rapid solidification, especially within the regime of thermal dendritic growth at DT J 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 thermodynamic 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.