Implementation of an Effective Bond Energy Formalism in the Multicomponent Calphad Approach

Published: November 26, 2018

Author(s)

Nathalie Dupin, Ursula R. Kattner, Bo Sundman, Mauro Palumbo, Suzana G. Fries

Abstract

Most models currently used for complex phases in the calculation of phase diagrams (Calphad) method are based on the compound energy formalism. The way this formalism is presently used, however, is prone to poor extrapolation behavior in higher- order systems, especially when treating phases with complex crystal structures. In this paper, a partition of the Gibbs energy into effective bond energies, without changing its confgurational entropy expression, is proposed, thereby remarkably improving the extrapolation behavior. The proposed model allows the use of as many sublattices as there are occupied Wyckoff sites and has great potential for reducing the number of necessary parameters, thus allowing shorter computational time. Examples for face centered cubic (fcc) ordering and the σ phase are given.
Citation: Journal of Research (NIST JRES) -
Volume: 123
Pub Type: NIST Pubs

Keywords

Calphad, compound energy formalism, effective bond energy formalism
Created November 26, 2018