Phase-field modelling and simulation of morphology transition induced by thermoelectric effects during solidification in pure metals

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

“…It should be firstly noticed that without current, the dendritic microstructure changes from the quadrilateral shape to the branching patterns as K increases, and the sidebranches are firstly enhanced and then compromised with large K. With induced current, the dendrite morphology changes in different patterns, which has been systematically discussed in ref. [19], and the side-branching also changes in different way with increasing K.…”

“…It has been discussed in ref. [19] that with induced current during the solidification in pure Sn and Bi, the dendrite formatting process would be changed in different patterns with increasing current density (A/m 2 ). As shown in fig.…”

“…Based on the model for dendrite growth in pure substances with applied direct current [19], the governing equation for the phase-field variable φ(r, t) (in solid phase φ = 1, in liquid phase φ = 0) is…”

“…Most recently, applying the electric field during metallic solidification became a promising way to control and modify the solidification process in order to optimize the microstructures [13][14][15]. Due to thermal phenomena which includes Joule, Peltier and Thomson effects, etc., heat may be emitted or absorbed during crystal solidification with an electric current passing through the sample [16][17][18][19]. It is has been proved that for different pure substances (Sn and Bi), the dendritic morphology shows different sidebranching characteristics with applied electric field.…”

“…It is has been proved that for different pure substances (Sn and Bi), the dendritic morphology shows different sidebranching characteristics with applied electric field. The reason for these structural differences is believed to be correlated to the thermal effect induced by the electric field, since the heat distributions near the interfaces would be more complicated with the applied electric field [19]. Thus, it is of great importance to characterize the microstructure, especially the side-branching characteristics, formed with applied electric field, in order to give insights on the electromagnetic solidification process control.…”