Influence of a Direct Current on the Solidification of Immiscible Alloys

Abstract:

Continuous solidification experiments were carried out with immiscible alloys under the effect of a direct current. The experimental results demonstrate that a direct current shows a significant effect on the migration of minority phase droplets (MPDs) in continuously solidified immiscible alloys. It can promote the formation of a well dispersed microstructure or a core/shell microstructure. A model describing the kinetics of the microstructure evolution in a continuously solidified immiscible alloy was developed. The microstructure formation in the alloys was calculated. The numerical results are in favorable agreement with the experimental ones. They demonstrate that a direct current may affect the microstructure development through changing the spatial motions of MPDs. The alloys show a well dispersed microstructure when they are solidified with such a direct current density that the direct current causing motion of the MPDs is almost equivalent to the radial component of the Marangoni migration velocity of the MPDs. The alloys show a core/shell microstructure when they are solidified with such a direct current density that the direct current causing motion of the MPDs dominates the migration of the MPDs along the radial direction of the sample. A wire or rod with well dispersed microstructure or a core/shell microstructure can be prepared by solidifying immiscible alloys under the effect of a direct current properly chosen.

• Periodical: Materials Science Forum (Volume 879)
• Pages: 2479-2484
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.879.2479
• Online since: November 2016
• Authors: Hong Xiang Jiang, Qian Sun, Jiu Zhou Zhao*
• Keywords: Direct Current, Immiscible Alloy, Microstructure, Solidification

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