A thermodynamically consistent approach to describe the effect of thermal vacancy on abnormal thermodynamic behaviors of pure metals: application to body centered cubic W

TL;DR

This paper presents a thermodynamically consistent model to describe how thermal vacancies influence the unusual thermodynamic behaviors of pure metals, demonstrated on body centered cubic tungsten, with potential applicability to other metals.

Contribution

A novel thermodynamic approach that accurately models the effect of thermal vacancies on metal thermodynamics across wide temperature ranges.

Findings

Reproduces nonlinear heat capacity temperature dependence.

Models nonlinear vacancy concentration behavior.

Validates approach with body centered cubic tungsten.

Abstract

In this paper, we developed a thermodynamically consistent approach to account for the Gibbs energy of pure metallic element with thermal vacancy over wide temperature range. Taking body centered cubic (bcc) W for a demonstration, the strong nonlinear increase for temperature dependence of heat capacities at high temperatures and a nonlinear Arrhenius plots of vacancy concentration in bcc W can be nicely reproduced by the obtained Gibbs energy. The successful description of thermal vacancy on abnormal thermodynamic behaviors in bcc W indicates that the presently proposed thermodynamically consistent approach is a universal one, and applicable to the other metals.