The influence of a direct electric current on the growth of solutal dentrites

P. A. Nikrityuk^1,2 - S. Ananiev² - K. Eckert² - R. Grundmann³

¹ Institute of Energy Processes and Chemical Engineering, Technische Universität Bergakademie Freiberg Reiche Zeche/Fuchsmühlenweg 9, 09596 Freiberg, Germany
² Chair of Magnetofluiddynamics, Institute of Fluid Dynamics, Technische Universität Dresden, Mommsenstr. 13, 01062 Dresden, Germany
³ Institute for Aerospace Engineering, Technische Universität Dresden Mommsenstr. 13, 01062 Dresden, Germany

Abstract
We study numerically the influence of an electric field on the dendritic growth during solidification of Al-4 wt.\% Cu alloy. The numerical results showed that an electric discharging applied during the solidification leads to the appearance of a micro-pinch force due to the complex shape of dendrite and difference in electric conductivities between solid and liquid phases. This pinch force is responsible for the motion of the {\it{interdendritic liquid}} in the form of a toroidal vortex near the dendrite tip. The fluid flow induced modifies the growth kinetics of solutal dendrites, namely, the sidebranching near the dendrite tip is enhanced and the growth of the main stem of the dendrite is suppressed. Figs 5, Refs 14.