Equilibrium segregation at coherent (1 0 0) interfaces in ternary fcc systems analyzed using the cluster variation method

Abstract

Citation for published version (APA): Kooi, B. J. (2003). Equilibrium segregation at coherent (100) interfaces in ternary fcc systems analyzed using the cluster variation method. Acta Materialia, 51(15), 4653-4665. DOI: 10.1016 Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. AbstractIn order to study equilibrium segregation, composition profiles around coherent (1 0 0) interfaces in ternary fcc systems were calculated using the cluster variation method within the tetrahedron approximation. A comparison with a previous regular-solution (RS) based model was made for interfaces between two disordered phases. This RS model overestimates the maximum atomic fraction of the segregant at the interface when its bulk value is Ͼ0.1. The oscillatory decay in segregant concentration from its maximum at the interface to its bulk value is much less damped in the case of the RS model. Analysis of the damping behavior leads to a very good agreement with results from free energy expansion approximations. Finally, the CVM calculations were extended to interfaces between ordered ternary fcc phases or anti-phase boundaries. Results for the interface between the L1 2 -Cu 3 Au(Ag) phase and a disordered Ag-rich phase in equilibrium at 583 K, and for a non-conservative APB in the same alloy, point to a strong suppression of order near the interfaces.

Multiphase solidification in multicomponent alloys

“…For solid/solid interfaces in dilute ternary alloys however, several interesting results have been reported: Kooi [62] discussed the equilibrium adsorption at coherent (1 0 0) interfaces in ternary face centered cubic systems analyzed using the cluster variation method in comparison to the regular solution model by Dreggia and Wynblatt [63]. Zhang et al [64] used the Monte Carlo simulation technique in junction with the embedded atom method to model the composition and structure of semi-coherent (1 1 1) and (0 0 1) hetero-interfaces in Ni-Ag-Cu alloys.…”