Solidification Morphology and Bifurcation Predictions with the Maximum Entropy Production Rate Model

Entropy (Basel). 2019 Dec 26;22(1):40. doi: 10.3390/e22010040.

Abstract

The use of the principle of maximum entropy generation per unit volume is a new approach in materials science that has implications for understanding the morphological evolution during solid-liquid interface growth, including bifurcations with or without diffuseness. A review based on a pre-publication arXiv preprint is first presented. A detailed comparison with experimental observations indicates that the Maximum Entropy Production Rate-density model (MEPR) can correctly predict bifurcations for dilute alloys during solidification. The model predicts a critical diffuseness of the interface at which a plane-front or any other form of diffuse interface will become unstable. A further confidence test for the model is offered in this article by comparing the predicted liquid diffusion coefficients to those obtained experimentally. A comparison of the experimentally determined solute diffusion constant in dilute binary Pb-Sn alloys with those predicted by the various solidification instability models (1953-2011) is additionally discussed. A good predictability is noted for the MEPR model when the interface diffuseness is small. In comparison, the more traditional interface break-down models have low predictiveness.

Keywords: MEPR; cellular morphology; coefficient of diffusion at high temperatures; growth velocity; maximum entropy production rate; morphological bifurcations at solid–liquid interface; planar morphology; temperature gradients.

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