Dendritic solidification and fragmentation in undercooled Ni–Zr alloys

نویسنده

  • P. K. Galenko
چکیده

Kinetics of dendritic solidification and fragmentation of dendritic crystals in undercooled Ni–Zr samples are studied. Using the capacitance roximity sensor technique and a high-speed-camera system, the dendrite growth velocity has been measured as a function of initial undercooling n solidifying droplets processed by the electromagnetic levitation technique. Analyses of solidified droplets give evidence to a transition from oarse grained dendrites to grain refined dendrites (CG-GR) at small undercooling, a transition from grain refined dendrites to coarse grained endrites (GR-CG) at moderate undercooling, and to a second transition from coarse grained dendrites to grain refined dendrites (CG-GR) at a igher undercooling. Predictions of a sharp-interface model are compared with the results of experiments on Ni–Zr samples. 2006 Elsevier B.V. All rights reserved.

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تاریخ انتشار 2007