Issue 5, 2023

Shapes of phases in isothermal phase diagrams: what is wrong with the Thermo-Calc logo

Abstract

The solubility of defects is essential to control the mechanical, electrical and thermal properties of engineering materials. The concentration of defects can be visualized on a phase diagram as providing the width to single-phase regions of compounds. Although the shape of these regions can have a tremendous impact on the maximum defect solubility achievable and guides the engineering of materials, little attention has been paid to the shape of the phase boundaries surrounding these single-phase regions. Here we examine the shape of single-phase boundaries that can be expected for dominating neutral substitutional defects. Single-phase regions in an isothermal phase diagram should be expected to be concave or star-shaped, or at least straight polygonal sides rather than be convex-like droplets. A thermodynamic justification is used to show the concave (hyperbolic cosine) shape depends on the thermodynamic stability of the compound when various substitutional defects dominate. More stable compounds have star-like phase regions, while barely stable compounds should be more polygonal shaped. The Thermo-Calc logo for example would be more physical if it contained a star-like central compound and pointed elemental regions.

Graphical abstract: Shapes of phases in isothermal phase diagrams: what is wrong with the Thermo-Calc logo

Article information

Article type
Communication
Submitted
09 Feb 2023
Accepted
02 Mar 2023
First published
06 Mar 2023

Mater. Horiz., 2023,10, 1875-1883

Shapes of phases in isothermal phase diagrams: what is wrong with the Thermo-Calc logo

A. H. Adekoya, S. Anand and G. J. Snyder, Mater. Horiz., 2023, 10, 1875 DOI: 10.1039/D3MH00195D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements