Induced side-branching in smooth and faceted dendrites: theory and Phase-Field simulations

TL;DR

This paper investigates how induced side-branching occurs in dendrites due to morphological disruptions, using theoretical analysis and phase-field simulations to understand the effects of capillary anisotropy shifts on dendritic growth.

Contribution

It introduces a theoretical framework and numerical simulations to explain the triggering of side-branching in dendrites caused by anisotropy variations.

Findings

Side-branching can occur in both smooth and faceted dendrites.

The angle of side-branching depends on the nature of capillary anisotropy shift.

Thermodynamic trade-offs influence dendritic instability.

Abstract

The present work is devoted to the phenomenon of induced side branching stemming from the disruption of free dendrite growth. Therein, we postulate that the secondary branching instability can be triggered by the departure of the morphology of the dendrite from its steady state shape. Thence, the instability results from the thermodynamic trade-off between non monotonic variations of interface temperature, surface energy, kinetic anisotropy and interface velocity within the Gibbs Thomson equation. For purposes of illustration, the toy model of capillary anisotropy modulation is prospected both analytically and numerically by means of phase field simulations. It is evidenced that side branching can befall both smooth and faceted dendrites, at a normal angle from the front tip which is specific to the nature of the capillary anisotropy shift applied.