Maximum entropy generation rate density and its application to microstructural evolution

TL;DR

This paper develops a maximum entropy production rate model for pure metal solidification, providing insights into interface structure, morphology transitions, and the effects of various physical parameters during phase change.

Contribution

It introduces a novel breakdown criterion based on maximum entropy production rate to analyze microstructural evolution during solidification.

Findings

Quantitative SLI thickness and entropy generation rate density at breakdown.

Correlation between solidification velocity and interface morphology.

Explanation of facet and non-facet morphology transitions.

Abstract

A solidification model based on the principle of maximum entropy production rate (MEPR) is considered for the study of pure metals. The approach leads to the development of a breakdown criterion which is able to account for the solidification velocity and solid-liquid interface (SLI) thickness. The quantitative knowledge of the SLI thickness and the maximum entropy generation rate density obtained at breakdown gives an insight about the structure of the SLI during solid to liquid phase transformation. The formation of facet and non-facet morphology, and their transitions are accounted for, which is a function of solidification velocity, heat of fusion, density and the crystallographic growth plane.