Modeling of gamma/gamma-prime phase equilibrium in the nickel-aluminum system

A theoretical model is proposed for the determination of phase equilibrium in alloys, taking into consideration dissimilar lattice parameters. Volume-dependent pair interactions are introduced by means of phenomenological Lennard-Jones potentials and the configurational entropy of the system is trea...

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Bibliographic Details
Published in:Acta metallurgica 1984-09, Vol.32 (9), p.1519-1525
Main Authors: Sanchez, J. M., Barefoot, J. R., Jarrett, R. N., Tien, J. K.
Format: Article
Language:English
Subjects:
Metallic Materials
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Summary:A theoretical model is proposed for the determination of phase equilibrium in alloys, taking into consideration dissimilar lattice parameters. Volume-dependent pair interactions are introduced by means of phenomenological Lennard-Jones potentials and the configurational entropy of the system is treated in the tetrahedron approximation of the cluster variation method. The model is applied to the superalloy-relevant, nickel-rich, gamma/gamma-prime phase region of the Ni-Al phase diagram. The model predicts reasonable values for the lattice parameters and the enthalpy of formation as a function of composition, and the calculated phase diagram closely approximates the experimental diagram.
ISSN:0001-6160