Phase Diagram Prediction of ΔfG0 for Inter Metallic Compounds: A “sensitivity” Analysis

Abstract

The prediction of the free energies of formation of intermetallic phases in binary systems typically involves assuming that the liquidus (or solvus) compositions in equilibrium with the phase are correct, that the measured thermodynamic properties of the adjacent solution are reliable enough to be extrapolated to different compositions and temperatures, that the thermodynamic solution model is of sufficient complexity to make such extrapolations accurate, and that the solid- solubility range of the intermetallic phase is negligible. These assumptions often conflict with the actual circumstances for a given system, leading to some question of how these errors would affect model-predicted ΔfG0values. Analysis of four binary systems (Ca- Zn, Al- Au, Ni- Ti, and Co-Sn) shows that poor-quality thermodynamic data has an especially strong impact on predictions, which can be exacerbated by the use of more sophisticated thermodynamic models. Compound nonstoichiometry and controversial liquidus compositions have less impact on modeling results. © 1994 ASM International.

Department(s)

Materials Science and Engineering

International Standard Serial Number (ISSN)

1054-9714

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1994 Springer Verlag, All rights reserved.

Publication Date

01 Jan 1994

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