A new model for the effective thermal conductivity of polycrystalline solids

TL;DR

This paper introduces a novel model for predicting the effective thermal conductivity of polycrystalline solids, incorporating grain boundary effects as an independent phase, validated by finite-element simulations showing improved accuracy.

Contribution

The new model uniquely treats grain boundaries as an autonomous phase with its own thermal properties, enhancing prediction accuracy over existing models.

Findings

Model accounts for segregation, doping, and interface transitions.

Finite-element simulations confirm higher accuracy.

Outperforms existing models in predicting thermal conductivity.

Abstract

A new model for predicting the effective thermal conductivity of polycrystalline materials is presented. In contrast to existing models, our new model is based on the thin-interface description of grain boundaries (GBs) and treats GBs as an autonomous phase with its own thermal conductivity. This treatment allows the model to account for the effects of segregation/doping, interface structural/phase transition, and interface decohesion on the effective thermal conductivity. finite-element simulations were performed to validate the new model. The simulations proved its higher accuracy compared to existing models.