Thermoelectric effects induced dendrite branching dynamics in pure substances: An insight from morphological theory

Abstract

Insights on the mechanical behavior in materials highly depend upon sufficiently characterizing microstructure details at the relevant length scales. In this study, the side-branching dynamics of dendritic structures formation in pure substances is studied upon the phase-field simulations of crystallization with applied direct currents. The effect of heat diffusion (including thermoelectric effect and undercooling) on the dendritic development is investigated, and the characteristics of the primary arms and side-branches are identified by implementing the image recognition technique. Results indicate that increasing the latent heat release would firstly enhance the side-branching and then cause the side-branches re-melting with large heat extraction form the solid. The side-branching could be tailored by rationally controlling the applied electric filed as well the heat treatment, which could be a potential way to improve the mechanical properties in metallic materials via optimizing the microstructure.