Phase-field modeling of growth pattern selections in three-dimensional channels

Abstract

In this paper, the anisotropic crystal growth in three-dimensional channels was studied using a thin-interface phase-field model. Different growth modes and dynamics behaviours, including planar front, stationary symmetrical single finger, oscillatory symmetrical single finger and multiple-finger structure, have been observed as the undercooling is increased. Lower boundary of undercooling for symmetrical single finger results from the tip-widening while the upper boundary results from the tip-splitting instability. Results show that the existence range of the symmetrical single finger depends on crystalline anisotropy, channel size and dimensionality. Moreover, an oscillatory instability, involving tip velocity and tip radius oscillations, was evidenced when the undercooling is close to but below the upper boundary. We found that the oscillatory symmetrical single finger strongly depends on the channel size and the crystalline anisotropy. Mechanism of the oscillatory mode has been discussed in details.

Keywords:

• solidification
• three-dimensional channels
• oscillation mode
• phase-field simulations

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 61078057]; the Fundamental Research Funds for the Central Universities [grant number 3102015ZY078].